Over the years I have tried many things and up until now nothing has worked to my satisfaction. Having said that, I have been sort of experimenting with the duration of the bottom paint and have recently extended the time between haul-outs to 30 months and I have found that the biggest impediment to this is the prop and shaft which look like a mussel farm after 24 months.
Normal anti foul will last a few months, International Trilux maybe a little longer but any ablative paint will wash off quite quickly. It's not about boat speed, it's about prop blade tip speed.
I am reliably informed by friends and colleagues that this stuff is the only solution:
My boat comes out in two weeks and I'm going to try it but unfortunately it will be two years before I can reliably report back.