Down our way we have several smaller races. Old Harry and the swash channel can get bad if an ebb spring hits an easterly wind, it isn't overly scary but can be uncomfortable. Next going west is Peveril which can get a little choppy, drifted through it once beam on and had the gunnels very nearly taking water over the side (26' boat) so gave up on that. Next along is Anvil point which can be at times nasty but the worst is St Aldhelm head which some call St Albans head, the worst along our stretch of the coast, avoid this on springs against the wind ie flood against easterly or ebb against westerly winds.
I have fished Portland race many times, now that can be scary as you have to go through the rough stuff to get to the fish. If just transiting this place is best tackled at or near slack water. If not then either keep very close in avoiding pots or go 5 miles offshore. Do your homework before fishing here.
The scariest races I have been through are around alderney. The Swinge is the one that has put the wind up me on several occasions. One time we had standing waves which had very little distance between them, one minute we were on top of a wave the next there was no water beneath us so we just waited for the crash then the next wave just wanted to breach us. Once you approach and think about this place its to late as the tides runs (up to 10 knots) very fierce taking us along once at over 10 knots on tick over but it can change in an instant. Dean and I are lazy leisure anglers, one particular day a few boats left Braye harbour to go to the banks fishing and went through the swinge. One boat had left his houdini hatch open and took a wave right over the top of the boat which soaked everything within his cabin. He was on the radio telling us how bad the swinge was. Dean and I left about 1/2 hour later and cruised through flat water at 22 knots with smooth water.
Alderney also has the Alderney race which can be horrendous with tides reaching 11 knots
The best way to deal with any race is read the weather and tides which both have an influence. Do your homework, read the water and take a change of underwear for when you get it wrong, which at some point you will