Over the last 35 years I have used virtually all types of antifouling paint on boats based largely on the East Coast and sometimes on the Solent.
My conclusion - the only one that ever worked really well on the East Coast was International's Extra Strong Hard Racing Copper (discontinued in the mid 70's), even TBT wasn't that good - always need two scrubs a year.
Most, even today's generation of weak watered down paints, seem to work fine on the South Coast and bottoms stay clean all season, but the moment you round North Foreland the slime starts big-time.
I keep my boat on a swinging mooring in the Walton Backwaters and over the last 6 years I have used International Optima, Blakes Ocean Performa, Awlgrip Gold Label, International Micron, Blakes Tiger. All have been equally pathetic at stopping slime (and once you've got the slime, the mudding starts!)- the slime always starts to show within 4-6 weeks after launching, irrespective of paint used!
A couple of years ago I added the (probably illegal) Starbrite Compound X, which is oxy-tetracycline (an antibiotic) this made a great improvement, but introducing antibiotics into the marine food chain is not really on.
This year after many discussions with virtually all the paint manufacturers, I am going to try Seajet Emperor, Seajet's Technical Dept tell me it is (purportedly) the best against slime & mudding - we shall see!
I think the real issue is that the Paint Manufacturers do most of their testing on the South Coast and formulate accordingly, some do test on the East Coast, but usually at Burnham, where there is a strong tidal flow and the water isn't very muddy. However for us poor souls on the rest of the East Coast with large amounts of silt held in suspension in the water and loads of fertilisers washing off the fields into the rivers, the Paint Manufacturers make no effort to create a product that works for us, they just know we write them a significant cheque every once or twice a year for an indifferent product.
Does anyone else have a view?

Hi David, I agree that in this as in so many other areas the East Coast is treated as the poor relation. If any of the paint manufacturers actually came up with an effective East Coast specific antifoul, they would make a fortune.

Seajet emperor has so far done a good job on my boat which has now been in the water for 4 months. Whilst the hull still slimes up. It releases as the boat moves through the water. I am based on the crouch and know just what you mean.
Its certainly got to be worth a go.

Yes I have found that Emperor seems to be working quite well, a lot better that anyone elses at the moment.
It also doesn't discolour so at least the boat looks sharp and smart.

Had Boat lifted out and found Emperor 034 has done a cracking job. I have just ordered my supply for the coming season