: I wanted to be able to sand the varnish off the hatches without having to
: work around the blocks. After I saw what I did with this one, I just used
: a chisel to pop the other blocks off. Its also easier to sand the blocks
: if they're off the hatches.

: Charles Robinson

Next time around consider swivel tabs around the perimeter to hold the hatch down. This leaves you with a flat hatch that's easy to varnish. If the hatch is too close on it's wide section to install a swivel you can use a 1" webbing with fastek buckle but configure an upside down slider near the edge of the hatch. That provides a similar effect of a raised piece of webbing on the slider pressing down on the hatch wherever it's located on the strap.
Imagine a piece of webbing starting from the deck going up onto the hatch and through the slider up to the Fastek buckle then back to the slider. With the slider upside down and not right side up it presses down the middle raised section of the slider. It may not provide the same amount of down force but with the swivel tabs it's kinda bomb proof in a belts and suspenders kind of way.
So instead of three straps and cam lever closures you could have four swivel closures and one webbing with fastek buckle. None of which provide the same exposed hook the metal lever closures present.

http://www.safetycentral.com/trigstrapsli.html