Re: SF Bay - how long do you get out of Pettit Trinidad SR?
I had my bottom painted with one coat of that paint, in blue (I recall that this matters.) 34 months ago. I've never had the bottom cleaned. When I hauled last week, there was a thin coating of green-brown growth, but it didn't look that bad; I suspect with cleaning it would have had some more time on it, but I'm not sure about another whole summer. (It seems that summer is when everything starts to grow.)
So I'd say 2-3 summers is about right, based on my one data point. I have no idea how much variance there is in this.
I keep the boat in Redwood City.
One thing that's pretty interesting is that the blisters on the bottom weren't nearly as bad as they were the last time I hauled. They were actually only slightly noticeable, and it's possible that they even sort of "dried up" a little. The last time I hauled, I had just bought the boat, and the bottom was in really bad shape; it may have been in the water for ten years. There was so much stuff on the bottom. I'm not sure if this could have been related to the blisters in some way.