Are the blocks of foam in the corners above deck necessary?

[SAABologist]

Hi, I am in the middle of replacing all the rotted wood in a 1987 16-foot MirroCraft Outfitter that I recently bought. Almost every piece of plywood was completely rotted. I have all new plywood treated with coats of diluted expoxy and wrapped in MariDek.

For simplicity I used all the old parts as templates and am keeping the original floor plan. It will be nice.

My question is, are the pour-in foam blocks that are above the deck and above waterline, necessary for stability or flotation?
There is a block of foam in each corner of the stern and one on each side of the livewell. Are these part of the safety design, or were they poured in just to fill empty space?

More details:

The bottom of the boat has a lot of foam in it below the deck. It's in good shape and I left it alone. There is foam all across the bottom for about 9.5 feet except for the middle channel for drainage to the bilge.

On either side of the livewell, which is in front of the steering console, there is a block of poured in foam. I can re-use them but am wondering if it is necessary to use them? These two spaces would make some nice additional hatches. The livewell is secured in place with plywood framing, all new.

In each corner of the stern, there also is a block of poured in foam. I can re-use these too, but I could also use the space for recessed rod holders and small hatches.

Can I delete the foam blocks or reduce them in size, or is it best to keep them?

Thanks much

 

[Scott Danforth]

The foam is there for flotation to keep the boat at the surface should you forget the plug, get swamped, etc. Without the foam, the boat goes to the bottom with a breach.

I would keep/replace the flotation foam

 

[SAABologist]

The foam is there for flotation to keep the boat at the surface should you forget the plug, get swamped, etc. Without the foam, the boat goes to the bottom with a breach.

I would keep/replace the flotation foam

Hi, I sure am keeping a lot of foam in the boat. I would not want to delete too much of it either, that's for sure.
In case I wasn't clear, all factory foam below the plywood deck is in place. It consists of 4 long channels of foam totaling about 40" wide and 9.5 feet long. The foam I am questioning is four blocks of foam (~ 15" x 15") in empty spaces in the stern corners and either side of the livewell.
Thanks for your reply.

 

[Scott Danforth]

remember, the factory tested the boat by intentionally sinking it.

from that test, they determined the amount of foam needed to keep the boat at the surface.

 

[zool]

Hi, I sure am keeping a lot of foam in the boat. I would not want to delete too much of it either, that's for sure.
In case I wasn't clear, all factory foam below the plywood deck is in place. It consists of 4 long channels of foam totaling about 40" wide and 9.5 feet long. The foam I am questioning is four blocks of foam (~ 15" x 15") in empty spaces in the stern corners and either side of the livewell.
Thanks for your reply.

If the boat swamps, those blocks wont be above the NEW water line

 

[SAABologist]

remember, the factory tested the boat by intentionally sinking it.

from that test, they determined the amount of foam needed to keep the boat at the surface.

Thanks again. I will keep that foam in place. It fits and is not a problem. The big blocks of foam in the corners of the stern would help keep the motor from sinking the boat. Onward!