Andy135

Targeting black bream with side-scan sonar.
As springtime progresses and the weather warms up I like to look for a calm spell of weather to fish for black bream, a delicious fish for the table and a very sporting fighter on appropriate tackle.
In late spring and early summer black bream will nest inshore over rocky ground, typically with a thin covering of gravel or light shingle. The males will sweep away the gravel to form a circular nesting site, which they carefully maintain to attract a mate. The female lays her eggs in the nest and the male guards them until they hatch.
When fishing for black bream it's often possible for recreational anglers to use side-scan sonar to find nesting sites on the sea floor. They tend to appear like a patch of circular, honeycomb-esque craters, as can be seen on the right hand side of this sonar pass. The usual side-scan sonar rules apply for best image quality; 3-5kts, flat calm, straight passes.

As soon as I spotted the nests above I circled back around and sent a line down. First drop and what a result!  This fine specimen graced the net.

A lovely male.
I was using a two-hook flapper rig with pennelled snoods and a single floating bead above the pennels, baited with squid strip. I find that 90% of the catches come to the lower snood, on the trailing pennel hook. I like to use floating beads as I believe it gives the squid strip a better profile when presented to a territorial bream.
That said, bream will also take lures quite readily. The fish below fell to a silver 30 gram slow jig drifted over the nesting site.

An important point about fishing over bream nesting sites – if a bream is taken from its nest, other fish will move in to eat the eggs within seconds, so if you’re catching & releasing it’s important to do so swiftly to give the bream every chance to return to his nest. If you’re catching for the table, then be selective and only take one or two fish in each nesting area to avoid fishing it out – after all this year’s bream eggs will be the future stock we want to catch in years to come.

Targeting black bream with side-scan sonar.
As springtime progresses and the weather warms up I like to look for a calm spell of weather to fish for black bream, a delicious fish for the table and a very sporting fighter on appropriate tackle.
In late spring and early summer black bream will nest inshore over rocky ground, typically with a thin covering of gravel or light shingle. The males will sweep away the gravel to form a circular nesting site, which they carefully maintain to attract a mate. The female lays her eggs in the nest and the male guards them until they hatch.
When fishing for black bream it's often possible for recreational anglers to use side-scan sonar to find nesting sites on the sea floor. They tend to appear like a patch of circular, honeycomb-esque craters, as can be seen on the right hand side of this sonar pass. The usual side-scan sonar rules apply for best image quality; 3-5kts, flat calm, straight passes.

As soon as I spotted the nests above I circled back around and sent a line down. First drop and what a result!  This fine specimen graced the net.

A lovely male.
I was using a two-hook flapper rig with pennelled snoods and a single floating bead above the pennels, baited with squid strip. I find that 90% of the catches come to the lower snood, on the trailing pennel hook. I like to use floating beads as I believe it gives the squid strip a better profile when presented to a territorial bream.
That said, bream will also take lures quite readily. The fish below fell to a silver 30 gram slow jig drifted over the nesting site.

An important point about fishing over bream nesting sites – if a bream is taken from its nest, other fish will move in to eat the eggs within seconds, so if you’re catching & releasing it’s important to do so swiftly to give the bream every chance to return to his nest. If you’re catching for the table, then be selective and only take one or two fish in each nesting area to avoid fishing it out – after all this year’s bream eggs will be the future stock we want to catch in years to come.

Targeting black bream with side-scan sonar.
As springtime progresses and the weather warms up I like to look for a calm spell of weather to fish for black bream, a delicious fish for the table and a very sporting fighter on appropriate tackle.
In late spring and early summer black bream will nest inshore over rocky ground, typically with a thin covering of gravel or light shingle. The males will sweep away the gravel to form a circular nesting site, which they carefully maintain to attract a mate. The female lays her eggs in the nest and the male guards them until they hatch.
When fishing for black bream it's often possible for recreational anglers to use side-scan sonar to find nesting sites on the sea floor. They tend to appear like a patch of circular, honeycomb-esque craters, as can be seen on the right hand side of this sonar pass. The usual side-scan sonar rules apply for best image quality; 3-5kts, flat calm, straight passes.

As soon as I spotted the nests above I circled back around and sent a line down. First drop and what a result!  This fine specimen graced the net.

A lovely male.
I was using a two-hook flapper rig with pennelled snoods and a single floating bead above the pennels, baited with squid strip. I find that 90% of the catches come to the lower snood, on the trailing pennel hook. I like to use floating beads as I believe it gives the squid strip a better profile when presented to a territorial bream.
That said, bream will also take lures quite readily. The fish below fell to a silver 30 gram slow jig drifted over the nesting site.

An important point about fishing over bream nesting sites – if a bream is taken from its nest, other fish will move in to eat the eggs within seconds, so if you’re catching & releasing it’s important to do so swiftly to give the bream every chance to return to his nest. If you’re catching for the table, then be selective and only take one or two fish in each nesting area to avoid fishing it out – after all this year’s bream eggs will be the future stock we want to catch in years to come.

Sea floor imaging: how to get the best from your side-scan transducer.
I don’t know about you, but I find “seeing” beneath the waves, and wrecks in particular, fascinating. I’m no diver, so this is probably the closest I’ll get to exploring the wreck itself, imagining her last hours as she sank and came to rest on the sea floor. Thanks to the capabilities of today’s recreational sonar equipment, high quality images of wrecks are easily within reach of the recreational boater and boat angler.
Configuring your transducer can be a minefield of options and settings. Generally, I find that less is more – most fish-finders are pretty well configured out of the box and I don’t find I need to tweak or change settings that often. There is however one caveat to that statement, and that’s transducer frequency.
Transducer Frequency: I use 455khz for general side-scan imaging – this tends to give the strongest returns, and therefore the brightest images, but I'll switch to 800khz when conditions are perfect and I want a really detailed view of the wreck structure. Here’s a side by side comparison of the same wreck (the Camswan in Sandown Bay, Isle of Wight, UK) at 455 and 800 khz. These images were taken using a Lowrance HDS9 Live chartplotter/fishfinder unit, coupled with a Lowrance Active Imaging 3-in-1 transducer.




As you can see, the 800khz image has better resolution, and is therefore more detailed, but is a fainter image than at 455khz.
You’ll notice the banana shape of the wreck in the first image. This is what happens when you change course during your pass over the wreck.
Scanning range: I've found that a side-scanning range of 60 metres gives a good compromise between being able to see far enough to either side in order to pick up objects and locate wrecks, yet still gives a bright and detailed enough image. The farther the range, the weaker the sonar returns will be, and therefore the poorer the image quality. You could tighten up the range to 30m or even less, but then it gets hard to pinpoint the wreck and you'll need to pass very close to the wreck to get a decent image.
Wave action can also affect the quality of the image you get. In the 800khz image above the wavy lines on either side of the sonar track are caused by the changing height of the transducer above the wreck, which is caused by waves making the boat rise and fall. In rough conditions the wave action can often cause fragmentation of the image, such as on this image of the Kurland below.


 
Weather conditions: Generally I find flat calm conditions at slack water best for side-scan imaging, and good conditions can bring out the best in your equipment. The image below was taken at slack water with very light winds – not quite flat calm, but not far off, and you can see the  resolution of the 800khz image really pops out, with very little fragmentation of the image due to wave action.

 
Boat speed: With fish-finders, the size of the objects they show on the sea floor is a function of time; the slower you pass over the object, the larger it will appear on the screen. The inverse is also true, as this image of the Highland Brigade below illustrates.

I buzzed over the Highland Brigade at 18kts. For those that don't know, she's quite a large wreck but see that that she's relegated to a relatively small blob of structure at speed - she'd be easy to miss, so it's always worth scouting an area at slow speed to pick up the wreck/reef/feature more clearly on the finder. I find a speed of 3-5kts about right for side-scan images.
Below is a side-scan pass of the same wreck, showing her true size. The image contains about 80m of wreckage and was taken at a speed of 4kts.

As you can see, the slower the pass, the bigger the wreck image - the transducer has more time to ping the wreck and collate the ping returns into useful images for us to view.
________________________________________________________________________________________________________________________________________________
In summary then, for best sonar image quality:
455khz transducer setting for brighter images 800khz for greater detail Side-scan range set to 60m for the best compromise between having the range to find objects and imaging them in sufficient detail calm weather conditions at slack water speeds of 3-5kts I’ll leave you with this image, again of the Camswan. The image is skewed due to a change of course during the pass, but what stands out is the ribs that are clearly visible sticking up from the wreck. Divers have confirmed their presence, and what this tells me is that she will likely be tackle hungry. For the angler doing a side-scan pass before drifting with lures, this will give you an insight into how you might choose to fish the wreck – with caution!

 

Targeting black bream with side-scan sonar.
As springtime progresses and the weather warms up I like to look for a calm spell of weather to fish for black bream, a delicious fish for the table and a very sporting fighter on appropriate tackle.
In late spring and early summer black bream will nest inshore over rocky ground, typically with a thin covering of gravel or light shingle. The males will sweep away the gravel to form a circular nesting site, which they carefully maintain to attract a mate. The female lays her eggs in the nest and the male guards them until they hatch.
When fishing for black bream it's often possible for recreational anglers to use side-scan sonar to find nesting sites on the sea floor. They tend to appear like a patch of circular, honeycomb-esque craters, as can be seen on the right hand side of this sonar pass. The usual side-scan sonar rules apply for best image quality; 3-5kts, flat calm, straight passes.

As soon as I spotted the nests above I circled back around and sent a line down. First drop and what a result!  This fine specimen graced the net.

A lovely male.
I was using a two-hook flapper rig with pennelled snoods and a single floating bead above the pennels, baited with squid strip. I find that 90% of the catches come to the lower snood, on the trailing pennel hook. I like to use floating beads as I believe it gives the squid strip a better profile when presented to a territorial bream.
That said, bream will also take lures quite readily. The fish below fell to a silver 30 gram slow jig drifted over the nesting site.

An important point about fishing over bream nesting sites – if a bream is taken from its nest, other fish will move in to eat the eggs within seconds, so if you’re catching & releasing it’s important to do so swiftly to give the bream every chance to return to his nest. If you’re catching for the table, then be selective and only take one or two fish in each nesting area to avoid fishing it out – after all this year’s bream eggs will be the future stock we want to catch in years to come.

Starting out fishing from your own small boat can be a minefield of things to learn and do. This guide explains the differences between the four types of sonar available to recreational sea anglers and how to select each one depending on intended use.
 
CHIRP sonar
CHIRP is the most common type of sonar that all fish-finders will use as a minimum. CHIRP sonar uses a band of frequencies to ping the sea floor and detects the differences in returns between each frequency. The fish-finder uses these returns to build up a more accurate “image” that you see on your screen. Typically using frequencies between 50-200khz, the bottom definition is usually pretty good, and usually good enough to distinguish between rock and muddy sea floors, presence of weed growth etc. The view generated by CHIRP sonar is that of whatever is directly underneath the transducer which is represented as a side-on view on your fishfinder screen.

CHIRP is generally effective at all boat speeds but transom-mounted transducers can suffer from image disruption at higher speeds because air bubbles and water turbulence under the transom make it harder for the transducer to send and receive sonar pings. Due to this I find CHIRP to be most effective at higher speeds when using a through-hull or in-hull transducer, where the water flow under the hull is cleanest and as such, turbulence and air bubbles are not an issue. The images above are taken using a through-hull Airmar M260 1kW transducer.
Effective depths of operation will vary with frequency – lower frequencies penetrate deeper than higher frequencies but for most UK coastal and offshore fishing any of the available frequencies will work fine. It’s only blue-water fishing in places like the US and Australia where sonar range can become an issue.
I tend to use CHIRP sonar when under way at speed and I'll keep an eye on it for any interesting drop offs or structure that I'll then do a slower pass over using down scan to get a higher definition view of what's there.
 
Down scan sonar
Down scan sonar uses higher frequencies than CHIRP – typically in the 455-800kHz range – and it’s the higher frequencies that give a higher definition image on your screen. Down scan sonar can distinguish between the various sea floor compositions and is also great at detecting structure (wrecks & wreckage, boulders, pilings and other submerged features). As a general rule, where there is structure there will be small fish, and where there are small fish, there will be bigger fish! The name down-scan is slightly confusing as the image on your fishfinder screen is a side-on view of whatever is under the transducer – best to think of it as scanning down under your boat.

I find that down scan sonar tends to work more effectively at slower boat speeds, up to 10-12kts max, and for highest image quality then 3-5kts is best.
Down scan sonar transducers are generally only available in transom mount configuration. There are a couple of through hull transducers that I’m aware of but the price of these is prohibitive when a perfectly good transom mount will do the job just fine.
The higher frequencies used for down scanning don’t penetrate to the same depths as CHIRP sonar, but again, for the type of fishing we do in the UK this isn’t a problem.
 
Side scan sonar
Like down scan, side scan uses the same high frequencies of 455-800kHz but this time the sonar pings are sent out sideways either side of your boat, and the sonar returns are represented on your fishfinder screen as a birds-eye view of the sea floor and water column either side of your boat. This view in particular is great for scouting for sea floor features, wrecks and structure. Most side scan sonar units have ranges of many tens of metres, often 60m or more each side. This means you have the ability to quickly search a swathe of sea floor 120 metres wide to find features that might hold fish.

Again, like down scan, slower boat speeds are best for side scan. I find that 3-5kts is perfect to give high quality, clear images of the sea floor. Transom mount transducers are most common for side scan, and I’ve found it important to locate the transducer on the transom in a spot that benefits from clean water coming out from under the hull. Any turbulence or bubbles will quickly degrade the quality of the image that the transducer is able to generate.
Also like down scan, the higher frequencies used for side scan sonar don’t penetrate to the same depths as CHIRP sonar, but this hasn’t prevented me from using side scan effectively for locating wrecks in the waters I fish off the south coast of the UK.
 
Live scanning sonar
A relatively new offering for recreational sea anglers, live scanning sonar interprets sonar returns in a similar way to hospital ultrasound scanners, presenting a view of the sea floor in real-time. This allows the angler to see his or her lure jigging under the boat and see fish move in to hit the lure in real-time. Various view configurations are possible, from a forward-looking birds-eye view of the sea floor in front of the transducer in wide and narrow configurations to a more traditional side-on presentation of a downward view.
This style of sonar was primarily designed with shallow-water lake fishing in mind, but I’ve heard reports from blue water anglers that live scanning technology can be used at impressive depths as well as in the shallows. Take a look at the Lowrance promo video of their Active Target sonar, and the Garmin promo video of their Panoptix Livescope sonar to see what's possible.
 

I made these a while back but thought some of us might find it interesting during lockdown. I needed a large, cheap SP lure body for use on a 6oz jig head for vertical fishing but couldn't find anything off the shelf that was suitable, so I thought I'd try pouring my own. I'd never done this before so it was a bit of an experiment.

The first stage was to make a mould I can pour into, so I needed to make a master of the lure.

Using Fimo I made the rough shape of the lure body, then baked it. After baking I used a Dremel with a coarse sanding drum, plus 320 grit wet & dry to get the final shape. After shaping I mixed up some fine filler paste to smooth out a few low spots before sanding smooth again. The finished master below.


Now I had the master, I needed to make the mould. So first I bedded the master into a block of plasticine. This is started by hollowing out an imprint of the master so that it fits snugly half way into the plasticine.



I added the shape for the pouring funnel in plasticine too. I ended up opening it out once the mould was finished as it was too narrow to pour smoothly.


The next step was to build up the sides of the mould around the plasticine block. I used the kids' Duplo bricks as they were quick and easy to assemble. I also added some ball bearings from the kids' marble run toy to make locating lugs for the two halves of the mould.
See that ball of plasticine at the top of the pic below? We'll come back to that....



At this point I also sealed up all the edges with small beads of plasticine to give a good seal. I then gave everything a light coat of vaseline to ensure the mould releases well once cured. Now ready for the first pour.

I worked out the volume I'd need and used an online converter to work out the total weight I'd need, then worked out the respective weights of RTV and catalyst. This is quite a large mould so I ended up needing needing nearly 400gr of silicone for each half.

After weighing out and mixing for a good 5 minutes the first pour went in.


 
After curing for 24 hours the first half was ready to pull.



Not bad at all. Pleased with the way the first half came out - fully cured, released well and no bubbles.

Next step was to prep the first half for the second pour. So, while keeping the master in position I rebuilt the mould sides again, remade the second half of the pouring funnel and re-lubed everything with vaseline. The second pour went in - very few bubbles, which is good.



Mould fully cured and separated after curing.


Next step was a test pour. I found that with a large SP like this I had to warm the mould by doing a scratch pour, which let the next pour flow much better.

 
First batch of lures from the new mould...



They all have an imperfection or two but as a first attempt I was pleased with them.
PS: remember that ball of plasticine I mentioned earlier? It went missing overnight after I had poured the second half of the mould - I originally put it down to having a semi-senior moment - did I put it away somewhere and forgot? It turned up eventually..... out of the back end of the dog . She must have snaffled it during the night when the first part of the mould was curing. Who knew that dogs like plasticine...??

Starting out fishing from your own small boat can be a minefield of things to learn and do. This guide explains the differences between the four types of sonar available to recreational sea anglers and how to select each one depending on intended use.
 
CHIRP sonar
CHIRP is the most common type of sonar that all fish-finders will use as a minimum. CHIRP sonar uses a band of frequencies to ping the sea floor and detects the differences in returns between each frequency. The fish-finder uses these returns to build up a more accurate “image” that you see on your screen. Typically using frequencies between 50-200khz, the bottom definition is usually pretty good, and usually good enough to distinguish between rock and muddy sea floors, presence of weed growth etc. The view generated by CHIRP sonar is that of whatever is directly underneath the transducer which is represented as a side-on view on your fishfinder screen.

CHIRP is generally effective at all boat speeds but transom-mounted transducers can suffer from image disruption at higher speeds because air bubbles and water turbulence under the transom make it harder for the transducer to send and receive sonar pings. Due to this I find CHIRP to be most effective at higher speeds when using a through-hull or in-hull transducer, where the water flow under the hull is cleanest and as such, turbulence and air bubbles are not an issue. The images above are taken using a through-hull Airmar M260 1kW transducer.
Effective depths of operation will vary with frequency – lower frequencies penetrate deeper than higher frequencies but for most UK coastal and offshore fishing any of the available frequencies will work fine. It’s only blue-water fishing in places like the US and Australia where sonar range can become an issue.
I tend to use CHIRP sonar when under way at speed and I'll keep an eye on it for any interesting drop offs or structure that I'll then do a slower pass over using down scan to get a higher definition view of what's there.
 
Down scan sonar
Down scan sonar uses higher frequencies than CHIRP – typically in the 455-800kHz range – and it’s the higher frequencies that give a higher definition image on your screen. Down scan sonar can distinguish between the various sea floor compositions and is also great at detecting structure (wrecks & wreckage, boulders, pilings and other submerged features). As a general rule, where there is structure there will be small fish, and where there are small fish, there will be bigger fish! The name down-scan is slightly confusing as the image on your fishfinder screen is a side-on view of whatever is under the transducer – best to think of it as scanning down under your boat.

I find that down scan sonar tends to work more effectively at slower boat speeds, up to 10-12kts max, and for highest image quality then 3-5kts is best.
Down scan sonar transducers are generally only available in transom mount configuration. There are a couple of through hull transducers that I’m aware of but the price of these is prohibitive when a perfectly good transom mount will do the job just fine.
The higher frequencies used for down scanning don’t penetrate to the same depths as CHIRP sonar, but again, for the type of fishing we do in the UK this isn’t a problem.
 
Side scan sonar
Like down scan, side scan uses the same high frequencies of 455-800kHz but this time the sonar pings are sent out sideways either side of your boat, and the sonar returns are represented on your fishfinder screen as a birds-eye view of the sea floor and water column either side of your boat. This view in particular is great for scouting for sea floor features, wrecks and structure. Most side scan sonar units have ranges of many tens of metres, often 60m or more each side. This means you have the ability to quickly search a swathe of sea floor 120 metres wide to find features that might hold fish.

Again, like down scan, slower boat speeds are best for side scan. I find that 3-5kts is perfect to give high quality, clear images of the sea floor. Transom mount transducers are most common for side scan, and I’ve found it important to locate the transducer on the transom in a spot that benefits from clean water coming out from under the hull. Any turbulence or bubbles will quickly degrade the quality of the image that the transducer is able to generate.
Also like down scan, the higher frequencies used for side scan sonar don’t penetrate to the same depths as CHIRP sonar, but this hasn’t prevented me from using side scan effectively for locating wrecks in the waters I fish off the south coast of the UK.
 
Live scanning sonar
A relatively new offering for recreational sea anglers, live scanning sonar interprets sonar returns in a similar way to hospital ultrasound scanners, presenting a view of the sea floor in real-time. This allows the angler to see his or her lure jigging under the boat and see fish move in to hit the lure in real-time. Various view configurations are possible, from a forward-looking birds-eye view of the sea floor in front of the transducer in wide and narrow configurations to a more traditional side-on presentation of a downward view.
This style of sonar was primarily designed with shallow-water lake fishing in mind, but I’ve heard reports from blue water anglers that live scanning technology can be used at impressive depths as well as in the shallows. Take a look at the Lowrance promo video of their Active Target sonar, and the Garmin promo video of their Panoptix Livescope sonar to see what's possible.
 

Sea floor imaging: how to get the best from your side-scan transducer.
I don’t know about you, but I find “seeing” beneath the waves, and wrecks in particular, fascinating. I’m no diver, so this is probably the closest I’ll get to exploring the wreck itself, imagining her last hours as she sank and came to rest on the sea floor. Thanks to the capabilities of today’s recreational sonar equipment, high quality images of wrecks are easily within reach of the recreational boater and boat angler.
Configuring your transducer can be a minefield of options and settings. Generally, I find that less is more – most fish-finders are pretty well configured out of the box and I don’t find I need to tweak or change settings that often. There is however one caveat to that statement, and that’s transducer frequency.
Transducer Frequency: I use 455khz for general side-scan imaging – this tends to give the strongest returns, and therefore the brightest images, but I'll switch to 800khz when conditions are perfect and I want a really detailed view of the wreck structure. Here’s a side by side comparison of the same wreck (the Camswan in Sandown Bay, Isle of Wight, UK) at 455 and 800 khz. These images were taken using a Lowrance HDS9 Live chartplotter/fishfinder unit, coupled with a Lowrance Active Imaging 3-in-1 transducer.




As you can see, the 800khz image has better resolution, and is therefore more detailed, but is a fainter image than at 455khz.
You’ll notice the banana shape of the wreck in the first image. This is what happens when you change course during your pass over the wreck.
Scanning range: I've found that a side-scanning range of 60 metres gives a good compromise between being able to see far enough to either side in order to pick up objects and locate wrecks, yet still gives a bright and detailed enough image. The farther the range, the weaker the sonar returns will be, and therefore the poorer the image quality. You could tighten up the range to 30m or even less, but then it gets hard to pinpoint the wreck and you'll need to pass very close to the wreck to get a decent image.
Wave action can also affect the quality of the image you get. In the 800khz image above the wavy lines on either side of the sonar track are caused by the changing height of the transducer above the wreck, which is caused by waves making the boat rise and fall. In rough conditions the wave action can often cause fragmentation of the image, such as on this image of the Kurland below.


 
Weather conditions: Generally I find flat calm conditions at slack water best for side-scan imaging, and good conditions can bring out the best in your equipment. The image below was taken at slack water with very light winds – not quite flat calm, but not far off, and you can see the  resolution of the 800khz image really pops out, with very little fragmentation of the image due to wave action.

 
Boat speed: With fish-finders, the size of the objects they show on the sea floor is a function of time; the slower you pass over the object, the larger it will appear on the screen. The inverse is also true, as this image of the Highland Brigade below illustrates.

I buzzed over the Highland Brigade at 18kts. For those that don't know, she's quite a large wreck but see that that she's relegated to a relatively small blob of structure at speed - she'd be easy to miss, so it's always worth scouting an area at slow speed to pick up the wreck/reef/feature more clearly on the finder. I find a speed of 3-5kts about right for side-scan images.
Below is a side-scan pass of the same wreck, showing her true size. The image contains about 80m of wreckage and was taken at a speed of 4kts.

As you can see, the slower the pass, the bigger the wreck image - the transducer has more time to ping the wreck and collate the ping returns into useful images for us to view.
________________________________________________________________________________________________________________________________________________
In summary then, for best sonar image quality:
455khz transducer setting for brighter images 800khz for greater detail Side-scan range set to 60m for the best compromise between having the range to find objects and imaging them in sufficient detail calm weather conditions at slack water speeds of 3-5kts I’ll leave you with this image, again of the Camswan. The image is skewed due to a change of course during the pass, but what stands out is the ribs that are clearly visible sticking up from the wreck. Divers have confirmed their presence, and what this tells me is that she will likely be tackle hungry. For the angler doing a side-scan pass before drifting with lures, this will give you an insight into how you might choose to fish the wreck – with caution!

 

I made these a while back but thought some of us might find it interesting during lockdown. I needed a large, cheap SP lure body for use on a 6oz jig head for vertical fishing but couldn't find anything off the shelf that was suitable, so I thought I'd try pouring my own. I'd never done this before so it was a bit of an experiment.

The first stage was to make a mould I can pour into, so I needed to make a master of the lure.

Using Fimo I made the rough shape of the lure body, then baked it. After baking I used a Dremel with a coarse sanding drum, plus 320 grit wet & dry to get the final shape. After shaping I mixed up some fine filler paste to smooth out a few low spots before sanding smooth again. The finished master below.


Now I had the master, I needed to make the mould. So first I bedded the master into a block of plasticine. This is started by hollowing out an imprint of the master so that it fits snugly half way into the plasticine.



I added the shape for the pouring funnel in plasticine too. I ended up opening it out once the mould was finished as it was too narrow to pour smoothly.


The next step was to build up the sides of the mould around the plasticine block. I used the kids' Duplo bricks as they were quick and easy to assemble. I also added some ball bearings from the kids' marble run toy to make locating lugs for the two halves of the mould.
See that ball of plasticine at the top of the pic below? We'll come back to that....



At this point I also sealed up all the edges with small beads of plasticine to give a good seal. I then gave everything a light coat of vaseline to ensure the mould releases well once cured. Now ready for the first pour.

I worked out the volume I'd need and used an online converter to work out the total weight I'd need, then worked out the respective weights of RTV and catalyst. This is quite a large mould so I ended up needing needing nearly 400gr of silicone for each half.

After weighing out and mixing for a good 5 minutes the first pour went in.


 
After curing for 24 hours the first half was ready to pull.



Not bad at all. Pleased with the way the first half came out - fully cured, released well and no bubbles.

Next step was to prep the first half for the second pour. So, while keeping the master in position I rebuilt the mould sides again, remade the second half of the pouring funnel and re-lubed everything with vaseline. The second pour went in - very few bubbles, which is good.



Mould fully cured and separated after curing.


Next step was a test pour. I found that with a large SP like this I had to warm the mould by doing a scratch pour, which let the next pour flow much better.

 
First batch of lures from the new mould...



They all have an imperfection or two but as a first attempt I was pleased with them.
PS: remember that ball of plasticine I mentioned earlier? It went missing overnight after I had poured the second half of the mould - I originally put it down to having a semi-senior moment - did I put it away somewhere and forgot? It turned up eventually..... out of the back end of the dog . She must have snaffled it during the night when the first part of the mould was curing. Who knew that dogs like plasticine...??

Sea floor imaging: how to get the best from your side-scan transducer.
I don’t know about you, but I find “seeing” beneath the waves, and wrecks in particular, fascinating. I’m no diver, so this is probably the closest I’ll get to exploring the wreck itself, imagining her last hours as she sank and came to rest on the sea floor. Thanks to the capabilities of today’s recreational sonar equipment, high quality images of wrecks are easily within reach of the recreational boater and boat angler.
Configuring your transducer can be a minefield of options and settings. Generally, I find that less is more – most fish-finders are pretty well configured out of the box and I don’t find I need to tweak or change settings that often. There is however one caveat to that statement, and that’s transducer frequency.
Transducer Frequency: I use 455khz for general side-scan imaging – this tends to give the strongest returns, and therefore the brightest images, but I'll switch to 800khz when conditions are perfect and I want a really detailed view of the wreck structure. Here’s a side by side comparison of the same wreck (the Camswan in Sandown Bay, Isle of Wight, UK) at 455 and 800 khz. These images were taken using a Lowrance HDS9 Live chartplotter/fishfinder unit, coupled with a Lowrance Active Imaging 3-in-1 transducer.




As you can see, the 800khz image has better resolution, and is therefore more detailed, but is a fainter image than at 455khz.
You’ll notice the banana shape of the wreck in the first image. This is what happens when you change course during your pass over the wreck.
Scanning range: I've found that a side-scanning range of 60 metres gives a good compromise between being able to see far enough to either side in order to pick up objects and locate wrecks, yet still gives a bright and detailed enough image. The farther the range, the weaker the sonar returns will be, and therefore the poorer the image quality. You could tighten up the range to 30m or even less, but then it gets hard to pinpoint the wreck and you'll need to pass very close to the wreck to get a decent image.
Wave action can also affect the quality of the image you get. In the 800khz image above the wavy lines on either side of the sonar track are caused by the changing height of the transducer above the wreck, which is caused by waves making the boat rise and fall. In rough conditions the wave action can often cause fragmentation of the image, such as on this image of the Kurland below.


 
Weather conditions: Generally I find flat calm conditions at slack water best for side-scan imaging, and good conditions can bring out the best in your equipment. The image below was taken at slack water with very light winds – not quite flat calm, but not far off, and you can see the  resolution of the 800khz image really pops out, with very little fragmentation of the image due to wave action.

 
Boat speed: With fish-finders, the size of the objects they show on the sea floor is a function of time; the slower you pass over the object, the larger it will appear on the screen. The inverse is also true, as this image of the Highland Brigade below illustrates.

I buzzed over the Highland Brigade at 18kts. For those that don't know, she's quite a large wreck but see that that she's relegated to a relatively small blob of structure at speed - she'd be easy to miss, so it's always worth scouting an area at slow speed to pick up the wreck/reef/feature more clearly on the finder. I find a speed of 3-5kts about right for side-scan images.
Below is a side-scan pass of the same wreck, showing her true size. The image contains about 80m of wreckage and was taken at a speed of 4kts.

As you can see, the slower the pass, the bigger the wreck image - the transducer has more time to ping the wreck and collate the ping returns into useful images for us to view.
________________________________________________________________________________________________________________________________________________
In summary then, for best sonar image quality:
455khz transducer setting for brighter images 800khz for greater detail Side-scan range set to 60m for the best compromise between having the range to find objects and imaging them in sufficient detail calm weather conditions at slack water speeds of 3-5kts I’ll leave you with this image, again of the Camswan. The image is skewed due to a change of course during the pass, but what stands out is the ribs that are clearly visible sticking up from the wreck. Divers have confirmed their presence, and what this tells me is that she will likely be tackle hungry. For the angler doing a side-scan pass before drifting with lures, this will give you an insight into how you might choose to fish the wreck – with caution!

 

Sea floor imaging: how to get the best from your side-scan transducer.
I don’t know about you, but I find “seeing” beneath the waves, and wrecks in particular, fascinating. I’m no diver, so this is probably the closest I’ll get to exploring the wreck itself, imagining her last hours as she sank and came to rest on the sea floor. Thanks to the capabilities of today’s recreational sonar equipment, high quality images of wrecks are easily within reach of the recreational boater and boat angler.
Configuring your transducer can be a minefield of options and settings. Generally, I find that less is more – most fish-finders are pretty well configured out of the box and I don’t find I need to tweak or change settings that often. There is however one caveat to that statement, and that’s transducer frequency.
Transducer Frequency: I use 455khz for general side-scan imaging – this tends to give the strongest returns, and therefore the brightest images, but I'll switch to 800khz when conditions are perfect and I want a really detailed view of the wreck structure. Here’s a side by side comparison of the same wreck (the Camswan in Sandown Bay, Isle of Wight, UK) at 455 and 800 khz. These images were taken using a Lowrance HDS9 Live chartplotter/fishfinder unit, coupled with a Lowrance Active Imaging 3-in-1 transducer.




As you can see, the 800khz image has better resolution, and is therefore more detailed, but is a fainter image than at 455khz.
You’ll notice the banana shape of the wreck in the first image. This is what happens when you change course during your pass over the wreck.
Scanning range: I've found that a side-scanning range of 60 metres gives a good compromise between being able to see far enough to either side in order to pick up objects and locate wrecks, yet still gives a bright and detailed enough image. The farther the range, the weaker the sonar returns will be, and therefore the poorer the image quality. You could tighten up the range to 30m or even less, but then it gets hard to pinpoint the wreck and you'll need to pass very close to the wreck to get a decent image.
Wave action can also affect the quality of the image you get. In the 800khz image above the wavy lines on either side of the sonar track are caused by the changing height of the transducer above the wreck, which is caused by waves making the boat rise and fall. In rough conditions the wave action can often cause fragmentation of the image, such as on this image of the Kurland below.


 
Weather conditions: Generally I find flat calm conditions at slack water best for side-scan imaging, and good conditions can bring out the best in your equipment. The image below was taken at slack water with very light winds – not quite flat calm, but not far off, and you can see the  resolution of the 800khz image really pops out, with very little fragmentation of the image due to wave action.

 
Boat speed: With fish-finders, the size of the objects they show on the sea floor is a function of time; the slower you pass over the object, the larger it will appear on the screen. The inverse is also true, as this image of the Highland Brigade below illustrates.

I buzzed over the Highland Brigade at 18kts. For those that don't know, she's quite a large wreck but see that that she's relegated to a relatively small blob of structure at speed - she'd be easy to miss, so it's always worth scouting an area at slow speed to pick up the wreck/reef/feature more clearly on the finder. I find a speed of 3-5kts about right for side-scan images.
Below is a side-scan pass of the same wreck, showing her true size. The image contains about 80m of wreckage and was taken at a speed of 4kts.

As you can see, the slower the pass, the bigger the wreck image - the transducer has more time to ping the wreck and collate the ping returns into useful images for us to view.
________________________________________________________________________________________________________________________________________________
In summary then, for best sonar image quality:
455khz transducer setting for brighter images 800khz for greater detail Side-scan range set to 60m for the best compromise between having the range to find objects and imaging them in sufficient detail calm weather conditions at slack water speeds of 3-5kts I’ll leave you with this image, again of the Camswan. The image is skewed due to a change of course during the pass, but what stands out is the ribs that are clearly visible sticking up from the wreck. Divers have confirmed their presence, and what this tells me is that she will likely be tackle hungry. For the angler doing a side-scan pass before drifting with lures, this will give you an insight into how you might choose to fish the wreck – with caution!