Ayuh,... I'm sorry you don't like my long winded replies,...
I'll be sure not to reply to your questions....
I've got more than just a few boat paint jobs behind me,...
I know from experince that Paint, is just fine below the waterline, especially on trailer boats...
Although, There's more than a few right here, that live in the water for 4 to 6 months a year...
The Hiliner I Painted 2 seasons ago, went into the water when the paint was less than a week old, 'n it's now spent 2 long seasons docked in the St. Lawrence, without the tiniest problem with it's Paint...
Above, Or below the waterline....