In a set of 30x30mm aluminium profiles I drilled holes for each 30 mm.
Instead of the moby hatch hold down system I have started on the bungee cord system. I have made 8 hooks and I will glue these in place on the hatches.
My plan for the hatch covers is to have the hatches held in place by Moby'es. It seemed a good idea to make the moby's tail short so it would have more moment and in that way a stronger grip.
I made a jig to hold the moby in the right angle for drilling.
To test the system I made a test hatch cover with the moby's in place. It was very difficult to put the hatch in place. It was difficult to hold the moby's while placing the hatch cover. I got so disappointed with my mockup that I decided to use Ros Leidy's under deck bungee cord system: