Do smaller I/O fiberglass boats have flotation foam?

[Another retired guy]

This may be a naive question but I have never owned a fiberglass boat before now. I see many references in threads to flotation foam but I don't see where it would be in my 20' Cuddy for example. The engine compartment is full width and transom is fully accessible. In front of that is the gas tank. In front of that is a step-down into the cabin, the shape of which follows the hull. The only "dead space" is below the cabin floor and on each side between the fuel tank and the cabin.
I've read that it would take approx 1.5 cubic yards of polyurethane foam to support 3000 lbs. anything less and it will sink so not much point in having it! I don't see where my boat has that much dead space.
So, do 18 to 24' approx i/o's have flotation foam?

 

[emoney]

Re: Do smaller I/O fiberglass boats have flotation foam?

It would be under the deck, between it and the actual hull. If you have a bilge area, that will give you an idea of how deep that area is around the stringers. Flotation foam doesn't create ALL the flotation; it just aids in it.

 

[metriccrescentwrench]

Re: Do smaller I/O fiberglass boats have flotation foam?

As I recall the requirement was for commercially manufactured boats under 20' to have floatation foam able to keep the boat afloat for something like 18 hours in the event it capsizes.

 

[Another retired guy]

Re: Do smaller I/O fiberglass boats have flotation foam?

Ok thanks. You are correct re the 20' size. I just researched Canadian boat construction standard and it only mentions foam being required in boats of 6 meters (19' 8" ) or less. So my boat, which is 20', does not require it. One less thing to worry about!

 

[Bob_VT]

Re: Do smaller I/O fiberglass boats have flotation foam?

A 20' boat built in the USA does have foam. If you are interested in what the purpose is and how it is tested you should google and read the USCG regulations. The foam keeps the boat swamped at a minimum and it actually floats at surface level. If you want to think that nothing can happen.....you could be dead wrong.

 

[Part-time]

Re: Do smaller I/O fiberglass boats have flotation foam?

The foam might not be just under the floor... My Century had about an inch thick of foam sprayed to the sides of the hull and under the deck as well. The foam is also used for support as much as floatation in many applications as well. Less plywood, less fiberglass, less weight.

 

[jigngrub]

Re: Do smaller I/O fiberglass boats have flotation foam?

One less thing to worry about!

Not necessarily, not only is foam used for floatation... it's also used for structural support as well. I'd be willing to bet money that your boat has a large amount of floatation foam under the deck and in the sidewalls below the gunwales. Your boat would be pretty floppy and hollow sounding if it didn't have floatation foam.

Just because it isn't required doesn't mean you don't have it.

 

[Another retired guy]

Re: Do smaller I/O fiberglass boats have flotation foam?

Not necessarily, not only is foam used for floatation... it's also used for structural support as well. I'd be willing to bet money that your boat has a large amount of floatation foam under the deck and in the sidewalls below the gunwales. Your boat would be pretty floppy and hollow sounding if it didn't have floatation foam.

Just because it isn't required doesn't mean you don't have it.

Good point re structural strength. I've just had a look at the original brochure for this boat and it says this :- "the hull is a special foam cored laminate of fiberglass inner and outer skins with a sandwich core of Klegecel ?? foam for stiffness and light weight" end quote. They claimed it was stronger and lighter than conventional fiberglass construction.
I guess I now know where the foam is !