I simply cut the botom of the hatch cover sides to fit my cabin top, as the hatch top reaches the hatch coaming . That way, with one foam seal on the cabin top, and another on the hatch top, and an inch of clearance between the hatch and the coaming, enough water would have to leak past the first seal to completely fill the gap, then make it past the second seal, to get in. Not much chance of that happening .