fixing a weed hatch leak

Underneath Eve's afterdeck is a dark, cramped place, where, if you pull the steps back and worm your way in, you will find the weed hatch. And if you unclamp it, you can see the propellor and the rudder.  This is useful if you need to clear an obstruction. But Eve's weed hatch seal is old and tired, and started to let water in.

here's the weed hatch removed; you can see the manky old seal.

I cut out a square from my old sleeping mat...

and stuck it into place using gorilla snot*

*silicone sealant, if you prefer