Underwater antifouling application?

May 16, 2015
100
C&C 37 28127 Port Madison, Washington
Nice warm day here in the upper BC Gulfs. Decided to dive on the prop & wipe the hull down. On the hull just above and forward of the rudder, I found a two chips in the antifouling exposing a total of 2 square inches of gelcoat. No other damage but I shudder to guess what hit the boat in that spot to cause both coats of 2-yr old Trinidad to chip down to gelcoat. Whatever it was, I didn’t hear it. It could be some fairing compound I overlooked with the primer, but doubtful.

So, questions: what is the risk of exposed gelcoat in coastal water over a 1-year period? Is there some magic underwater application that can be a shield until fall 24?
Pete
 
Jan 11, 2014
12,961
Sabre 362 113 Fair Haven, NY
No significant risk. There will be some growth on the spot, it will come off easily.
 
Jan 4, 2006
7,268
Hunter 310 West Vancouver, B.C.
what is the risk of exposed gelcoat in coastal water over a 1-year period?
Nothing worth worrying about.

When I first got my boat new in 2098, it was continuously shedding bottom paint as the bottom had only been chemically etched at the factory. The hull wouldn't hang on to bottom paint for love not money. The norm was to see 1/4 of the hull without bottom paint each year it was hauled out. The slime and growth was minimal on these areas and brushed right off

The one thing I would advise against is any goop you can apply on a temporary basis to keep the area clean. If it has greasy properties, and many do, it will ensure bottom paint will never stick to that area again.
 
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