John,
I gotta tell ya man that this stuff is tough.
3-4 years ago, I found a 2-part topside paint from a company called w/logo "Top Secret."
Checking them out, I found that they had just recently went commercial. Until this time,
their deck painting was primarily for military ships for the Navy & Coast Guard.
They may have changed their logo name since but, this stuff has been bullet-proof thus far for me.
The secret though is in proper preparation first. I see folks unhappy with their re-coat project but asking them for details, they failed in the correct preparation. I did my project right at the dock.
Here is their link John,
Read & See what you can find out pal.
http://www.topsecretcoatings.com/
Let me know............
CR