I have recently acquired an older H18 for free and there are a few soft spots next to the trampoline in the hull. I have read most of the help here on the forum already.

My Idea:
I was thinking that you could cut open a square section on top of the hull where the soft spot is and drop in a pre-fabbed fiber glass box that is insulated. and fiberglass that section of the hull to build it stiff/ stronger. then on top putting in a recessed hatch so that you are essentially turning a soft spot into a in-hull cooler....

would this idea be feasible and work? Anyone have any input or suggestions for this idea? btw, im not really worried about the boat being the perfect racing machine. thanks

That would work probably, if your main goal was to put in a cooler and wanted to learn some serious fiberglassing in the processs. If you just want the soft spot fixed I would stick to the simple, tried and true epoxy injection method as described here: http://www.thebeachcats.c…ms/viewtopic/topic/12493

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Dave Bonin
1981 Nacra 5.2 "Lucile"
1986 Nacra 5.7 "Belle"
Winnipeg, Manitoba, Canada
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Check out the Hobie Getaway, they have a cooler in each hull. Maybe you can purchase 2 and install.

thanks for the quick reply and help

i want to put a cooler and/or storage compartment in the hulls but i wanted to make sure i wasn't going to be sacrificing the structural integrity of the boat too. Would y'all have any technical advice on the best way to do it?

I don't think there is a problem with structural integrity. As long as you beef up the area around the cutout, you will maintain the stiffness & integrity of the hull.
Last fall I went out to L.A. to buy a used set of sails for my 5.7. The chap selling them looked to be in his 60's, & after several hours of talking & showing me his enormous cat graveyard/parts bins. I mentioned Tim Rolland, AKA NACRA. He pulled an old photo off the wall, signed by Mr. Roland, a 30 some ft Cat that they were test driving before some record attempt. His company built battens for NACRA, & he still builds graphite battens, showed me a bunch, lots of $$$.
He knew Canada, as he had sailed Tornadoes in the Worlds, "as a younger man, up on Lake Ontario. We were in second place, til the wind howled, then the Aussie killed us all, man they know how to sail in heavy weather."
He asked if I wanted to walk up the road & see his latest creation. It turned out to be a NACRA 6.0, all carbon, each hull was 65 lbs. Carbon mast, 37 lbs., "$50,000 worth of sails in that loft." I could have spent days there.
He had built "cooler hatches" into each hull. What I remember was being handed the hatch, I was impressed with how light it was, it felt like a piece of styrofoam. He was as impressed by the stiffness, "try to twist that". He mentioned that graphite was capable of doing it with no extra thickness, but with fibreglass, you would have to beef up the perimeter a bit.
The hatch cover was nearly side to side, a loose fit, so integrity did not depend on the cover being securely in place. I would clean up the undersides & lay a few extra layers around the perimeter. Having a narrow hatch, with an inch beefed up on each sidewall should work.
I would attach some sort of foam to the hatch, or bulid 6 of them

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Hobie 18 Magnum
Dart 15
Mystere 6.0XL Sold Was a handful solo
Nacra 5.7
Nacra 5.0
Bombardier Invitation (Now officially DEAD)
Various other Dock cluttering WaterCrap
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I would agree with wolfman. If it's your first time try simple and make sure you like ur boat before putting a lot of work into it.