I just had a discussion with the diver who does the bottoms of hundreds of boats in the area. Some interesting things emerged from the chat.
Boat yards do NOT like and many do not allow divers to do the bottoms of their customers.
The cost he charges on a one time rate is $2.25 /ft. So a 35' boat to be scraped and re zinced is $80 plus the zinc. Racers have hard bottoms and clean up real well, but are scraped every week or two.
But they don't need annual haul out
and yard work
, masking, blocking painting. This can cost for a 35' boat from 1,200 to 2,400 depending on the paint
and the number of applications and bottom prep work
Let's tale the low mid cost of say $1,600. That's would buy you 20 bottom scrubs from a diver who inspects your boat each week for about 5 months. No paint, no pollution and no work for the yard either.
I think it makes sense NOT to paint, but to have a diver scrape your bottom every week or two. And if you can do it less you are ahead of the game
and the environment