Totally agree with you that cleaning in water can shed not so nice chemicals. Boats in general are not the cleanest of objects floating in the water, but they are getting better. Also agree we are in totally different environments. Boats in my area are not in the water all year, most are 6 months tops. So the boats with fouling paint really don't need cleaning. The only growth we have is hair algae and zebra muscles.
The boats I do clean are not designed to be in the water all the time. They are strictly racing vessels, but because of there use find themselves in the water all the time. A pure bread racer will have a polished epoxy bottom to reduce drag in the water. So we do have something in common, using the softest cleaning method possible to get the job done. After a few years of trying different things we found a soft bristle brush does the best job with almost no micro scratches done to the coating. It also removes the least amount of paint from vessels that are painted. And we tried tons of stuff, from wash mits, shammies, all types of scotch brite, and brushes.
I'm a diver first, the enviroment is my primary goal, I enjoy diving, I don't want to wreck it. I also race sail boats, and clean them, but keeping goal one in mind at all times.
I'm not a stud, my wife cleans with me in a wet suit as well

We just find if we work hard enough we stay warm even in colder waters. For normal diving I wear a dry suit until 65 degrees. We are also in and out of the water in about an hour most times. Most we have been in the water cleaning was about 3 hours, but still stayed warm.
May I suggest learning dry suit repair and keeping some stuff on hand. It has saved my butt a few times being able to throw on a new seal or patch a leak that night.
See this was educational for both
