Can someone tell me what the fiberglass bump/roll is on port/aft bilge area of C 22?

Sep 30, 2025
173
Catalina 22 Davis Hollow - Lake Arthur
I'm trying to figure out where and how any excess water collects in my 1971 C22. Does this "bump" have anything to do with excess water? Is it just for structural support?

Also whats under the Gas platform...just empty space I'm guessing.
 

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May 17, 2004
6,108
Beneteau Oceanis 37 Havre de Grace
My guess is the bump is acting like a stringer to give the hull some stiffness. The bottom of the hull is probably pretty thin laminate, so stringers are used to hold the shape.

Empty space or maybe closed cell foam are good guesses for what might be under that platform.
 
Oct 19, 2017
8,107
O'Day Mariner 19 Littleton, NH
Those look like some sort of garboard stiffening stringer. They may be built up to confine spills or something like that. Do they not run forward along most of the hull or does the berth/bench just continue the structural effect?

They may also be intended to reinforce the hull for trailering. Their placement would both support the ballast, and reduce denting from the trailer rollers.

But, that is just a guess.

-Will
 

Joe

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Jun 1, 2004
8,304
Catalina 27 Mission Bay, San Diego
I'm trying to figure out where and how any excess water collects in my 1971 C22. Does this "bump" have anything to do with excess water? Is it just for structural support?

Also whats under the Gas platform...just empty space I'm guessing.
The most common way to detect the source of leaks is the powder method. Try dusting non toxic baby powder in the suspected areas of water entry. The powder will show the invisible water trails, like fog on a mirror. Check around the portlights (windows), hatches, mast step, any place you can imagine water might find its place into the boat. Check your tanks, if there are any. Also, consider condensation... a concern in areas of high humidity. You'll want to make sure the interior stays ventilated to help with that. There are a few anti humidity devices available for boats. Browse through the chandlery catalogues for examples. Anyway, give the powder method a try,
 
Sep 25, 2025
3
Catalina 22 Ithaca NY
I'm trying to figure out where and how any excess water collects in my 1971 C22. Does this "bump" have anything to do with excess water? Is it just for structural support?

Also whats under the Gas platform...just empty space I'm guessing.
That is the liner. The bump keeps your stuff from sliding into the deep unknown.
 
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Sep 30, 2025
173
Catalina 22 Davis Hollow - Lake Arthur
That is the liner. The bump keeps your stuff from sliding into the deep unknown.
I guess what I'm trying to figure out is why is the bump "open" on my boat. If I'm looking down by the keel winch rubber tube, at the bottom, I can see a dark, black hole (2' diameter) that is the opening of this BUMP. I can't see into it more than a few inches, but its open space and worries me that in there, and also down under the fuel tank platform (which it seems the bump leads to), is just open space that could have water in it and just festering mold.... and there is no way to know or to clean it. Only paranoid because I have issues with mold and any mold in the air makes me really sick now. I normally wouldn't care and just not worry about it but....

Is the bump' open on other boats? Should I just seal this little hole up so that area can not take any (more) water?