I was at Lowes looking around for things I didn't need and came across a roll of self-adhesive insulation tape (for hot water pipes?) that would work perfect for hatch gaskets. It's called Rubatex Insulation Tape. It's 2" wide x 1/8" thick x 30' long - feels like neoprene. Costs about $7.50. It's in a blue box next to the hot water heater insulation blankets. I bought a roll while the gittin was good.

Ross