I like painting with good brushes, so I choose a nice one to finish painting the last coat of bottom paint on the centerboard for the sneakbox. Turns out it was a varnish brush, never meant to touch anything less holy than that clear amber stuff. Washed it out in 3 rinses of thinner followed by zylene. We have these nice brush spinners to get the solvent out, which is settled, filtered and used again and again. Thats sustainable.
Bottom paint is a problem though. It is made to be toxic to marine life. You don't want stuff to grow on the bottom of your boat or those pesky wood eating mollusks to make their homes inside your hull since their drainage holes let water in. Borers used to not be as prevalent here, but with the warming of the waters, thermal discharge from power plants, and melting ice caps the tropical worms are moving north. Besides borers anything like barnacles, grass, weed, slime, etc. slows you down because it drags in the water. A boat left in water all summer would have about a foot of growth by the end of summer without a good bottom paint.
I avoid the issue of bottom paint by not keeping my boat in the water. It is small enough and has the right configuration to live on a trailer. I pop it in the water when I want to row or sail. Keeping it on land has some other advantages too. I can take it with me when I visit new places. A good reason is that I avoid having heavy ground tackle and higher insurance costs. The boat is less subject to damage from the twice a day tide changes and river currents that bring debris from upriver, not to mention wakes from passing tugs and barges. Even though the Delaware is a busy thoroughfare, there are plenty of small coves and quiet places.
Another note, before bottom paint, builders would nail copper metal to the undersides. Expensive and heavy, but this protected the British Navy and others that traveled in tropical waters. Before that and for those on the cheap, the traditional coping mechanism with bottom growth was the haul out and bottom scraping. Mechanical removal of marine growth took plenty of sweat equity.