The Ultima60 needs to be stirred a lot thats all. You should only put small amounts at a time in the roll pan.
In you situation I am not sure I would use the Ultima60 or 40 because of the current which is constant and swift where you dock. Do you ever have a diver go under the boat or do you? How much time will you spend in real salt water docked? Whats your boat look like when you take her out of the water every year before its pressure washed?
I've thought about hiring a diver but never got around to it because performance was never noticeably bad.
At the end of the season when we haul out I have a thin, smooth layer of green slime just below the waterline, exdending down a about a foot below the waterline (presumably where sunlight is available). It washes off easily with my pressure washer, and in fact one of the nice things about Pettit Vivid is that it holds up very well to the pressure washer.
We've never had any barnacles or grass - just the smooth layer of slime that builds up during the season.
Hoping to get into the bay a couple times this year, for a total of 4-8 days. In addition to that, we do head south to the saltier parts of the river a couple times a year.
We are at mile 88 on the river. Today the salt line
(250 mg/l chloride content) is at mile 70 (just north of Delaware Memorial Bridge). I think I have seen it get as high as mile 80 during a dry summer.