Unsinkable.

I hope I don't bore anybody with my comments but this is the unsinkable setup that I was considering.

A bag is made from fine mazed netting (screen door netting) that sits more or less in the hull between the two bulkheads supporting the beams. This netting is filled with small balls of foam packing material that the industry uses. I think we all know this stuff. The netting is there to prevent the balls from escaping through any large crack in the hulls.

As this foam is in small ball format it can always be taken out through the inspect port and be replace by new balls when it ages or has soaked up to much water of time.

This granulate can even be made yourself by breaking up styrofoam. Typically common variaty styrofoam weights 10kg/cubic meter. I checked that a while ago. This means that even if the complete hull is filled (about 300 liter) that the stuff will only weight 3kg in total. Of course 150 kg floatation will be quite enough (1.5 kg per hull).

Wouter