Re: Cleaning Hull in the water
I have cleaned my hull by dragging a cheap tarp under it ,letting the poly tarp float up against my hull, then pouring a gallon of bleach in it and leaving it overnight. Next day all growth fell off. Works for weeds but not barnacles.
At sea, one can pull a rope under your forefoot and saw it back and forth across the hull working your way back to the keel, then doing the same from the keel to the skeg. Doesn't get everything, but removes a lot, if the growth is thick and heavy.
Brent Swain, Boat designer, Builder, and author of "Origami Metal Boatbuilding"