: I am beginning hatch construction on my latest boat and I will be
: using rare earth magnets. I have 1/8" x 1/2" round I
: plan to use placing about 10 pairs per hatch.

I used 11 pairs and not even close enough to hold hatch. Bigger mags or at least 14 / 16 pairs to get a good seal.
Although disjointed about the mags I have a great hatch lip with carbon fiber finish. I will go with interior bungee on this boat.
: Robert, visionary