Hi Bill,

Depends on what you're doing with the boat, if you're just out paddling my hatches stay dry too, even in waves. If I'm rolling (or more likely trying to roll) they get wet.
Bill H.

Your not wrong!I worry too much but I often tie my clobber to the "floor"under the hatches so that when upside down...the clobber "shouldn't" pop the hatch seal by falling on the under side of the hatch.I don't do upside down much but that's when "flee or fight" makes me panic.Clobber tied down is my peace of mind,so in theory, I can set up for my unreliable roll without at least one mental distraction.
My shock cord closing system is a continuous loop making a rectangle on the "floor" so some of the shock cord can be used to keep the clobber in place .This consumes some of the elastic so the hatches get more force as a happy consequence.
I did get a leak, last week, and got philosophical until I found my water supply kept in that compartment had it's top loose,one of those sucker types! I tasted the small puddle after that .Fresh drinking water.
I guess rapid bulk water ingress is the real concern,like loosing your hatch altogether.
cheers from Paul.