Quite right. There is expading flotation foam in both ends of my G. It doesn't keep the water out during rolling, but it does prevent it from escaping afterward. Inflatable bags with long tubes are a better idea, since they can be deflated to allow air circulation all the way out to the ends.

: I've used hardware store insulation expanding foam in my composite boat, but
: would hesitate to use it in a wooden boat. It works in taking up space,
: and it generally excludes water in its own volume. But you're never going
: to get a complete fill, you will keep some water in the boat up against
: the hull on an extended basis, and that just doesn't seem like a great
: idea. Additionally, you'll grow some really neat life forms that have
: never before been seen!

: Wouldn't do it.

: Jack Martin