Hi Marcus,
Nice Pic! I'm amased that you guys built the 18 with 4mm ply as I would have thought you'd get better stiffness with 5 or 6 and still be under weight. Or is the bending the problem with thicker ply?.

Also if you've got to drop 20kgs then where will that go from (apart from the obvious extra 2ft)?

Would like to see more of your 18 and 16 construction photos as you get round to it.

Cheers Phil