flotation foam

I have a 14′ Crestliner that I use in the bwca. It appears that the person I bought it from removed the foam in the back to add storage but maybe there was never any there. I have used it this way for years and was just aware that waves would come over the back in certain situations. I have now added flip down portage wheels and the concern has grown.

I would like to keep some storage back there for a trolling motor battery and other misc stuff. Basically just a battery box on each side.

Does anyone have recommendations on how and what to fill the cavities?

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Are you trying to increase flotation, deaden sound, or just fill a void for the sake of it? Foam in the boat only helps if you’re taking on water so you don’t fully “sink”. You’ll be wet and swamped but the boat shouldn’t go all the way down. It doesn’t increase how far out of the water the boat will be if you aren’t taking on water. If you want it to help prevent water coming over the back, you’re actually making it worse by adding the weight of the foam. You’d be better off running wires for batteries to be placed in the bow to “balance” your loading.

That said, if you want to foam it up you can get the two part closed cell marine foam, throw a divider in where you want to still have room, line it with contractor plastic, then pour it in. Don’t fill it all the way full, as the foam expands. Or you can take closed cell board foam (pink insulation foam board) and cut pieces to fit.

Is there foam underneath the other seats?

For something such as what you’re describing I may just get a 4×8 sheet of 2inch blue or pink foam and cut it to fit in areas. One excellent place I see is right under the seat. Make a block to fit in and fill that opening just make sure you leave a few of the center ones short to allow water to drain through. May need to tape it all together with foil tape and install a couple aluminum bars across the opening to hold everything in.

Also if you’re really worried about it get a small bilge pump, especially since you’ve already got batteries.

Also just incase you didn’t already know the BWCA only allows portage wheels on select lakes/portages.

Lost nailed it. Water displacement is what keeps the boat afloat during typical use. Foam will only keep the boat afloat should you capsize.

Think canoes and Jon boats.

ClownColor wrote:

Foam will only keep the boat afloat should you capsize.

Not true. It will also keep it floating if it starts taking on water.

Thanks guys. I am looking to increase the freeboard in the back of the boat. When I have my portage wheels on and turn they hit the water. I have not had that happen on other boats with flip down wheels on. It seems like since there isn’t foam in these areas the back of the boat doesn’t float as well. There is foam under the seats. Maybe it is ok and I will just have to continue to be aware in certain situations.

If thats the case then moving the batteries forward will help more than anything.

You will want to bring weight forward if the back doesn’t float well. Move the batteries to the front. Also when you are packing your boat, try to put heaver items closer to the front.

Adding foam in the back won’t do anything to give you more freeboard. That is a function of hull shape and it is what it is. All you can do is as others have suggested, move weight forward in the boat.

But I would absolutely want to add foam back into those compartments if it has been removed. For no other reason than safety. If those compartments were full of foam and they were stripped out, you have probably lost 30% or more of your flotation, which may be enough to be the difference between the hull staying afloat or sinking.

Grouse

Thanks everybody!