I'm loving these ideas. I use to look after our water ski racing boat years ago so I can work with epoxy I've even seen boats made from balsa wood, epoxy and glass fibre. I could be tempted to do an interesting build from unusual materials another day. Keep these ideas coming my imaginations going wild here.

Eddy' did you find any drawbacks in rigidity across the y axis with your open ended design? I was thinking it had to be a box type design but you have 100x50 box section on the X axis and nothing at the ends on the Y axis. I like this idea!