Thanks for all response. It has given me a lot to think about. It sounds like a good
idea to put the gasket in the hatchcover and to let it be a little bit bigger than the lip.

The neoprene has a width of about 20 mm and I´ve bougth the material from the
Diving center next door. I suppose it do absorb water and that might be the problem.
But I suppose all neoprene absorb water- thats the way wetsuits keeps you warm,
or? Is there another material that is better. Is it better to use some the kind of rubber
gasket you find in cardoors?

Fritjof