Eric,

Very interesting pics and info. I used full length groomets for lacing once.
They were secure, but the lacing up took forever. I then went to handmade
aluminum speed lacing. It was much faster, but they made the flap look lumpy.

Recently, I've been using just a 2" Velcro flap and extended "X"
pattern deck rigging. This combination is easy to make, quite water
tight, and secure.

As you probably already know, there is little or no pull-apart stress in
the deck to begin with, plus the lacing has little impact on tightening
the skin. I'm putting a large zipper in my newest boat,covered with a small
flap to make it even more watertight for rolling.

Thanks for sharing your knowledge. That way we all benefit.

Tom