I made the Ghost Train at just over 1 meter long, and it is a lot lighter han my IOM. I will some insulation and see how it goes! Shall I seal up the hole at the back? Point the back? I saw your useful diagram about what to do for the front (bow, I mean).

Hmm - I just realied now that I built the mast for a 48 inch boat (or whatever it is meant to be), while the boat is 1 meter...

Oh well - thanks for all the help about floats!