I have an unopened 3litre tin of dark blue International Cruiser Uno antifoul purchased middle of 2015 no longer required £50 It is probably too expensive to courier but can be collected from Frinton or Potters Bar.
I used it last season.
Apropos the thread about antifoul....
In fairness, there is a heck of a lot of silt in the water around us.. Possibly on account of dredging the marina or the clam fishermen. .. and Tomahawk has almost vertical sides which do trap a lot of light...