: The ply is a little thicker than is called for on the plans,
: 1/2" would be lighter and plenty strong, specially using a
: heavy wood like birch.

: Bill H.

True, true!!! But like most things I build, I over-build. The 11mm was just below the 1/2" so I rounded up to the 17mm. Better to be a little heavier in the scantlings than to be always wondering if the thing is strong enough, I say! Plus, Dave's Disko Bay only has 6 frames, so the extra weight won't be a factor.

Sean