Re-sealing hatches

[SeacraftErik]

Looking to seal up my deck hatches but wanted to see how these hatches functioned originally.

My plan is to remove the 2 captains chairs, replace with a leaning post and a fiberglass bait tank right behind it (above deck), epoxy and gelcoat the holes, screw down the forward hatch and seal the edges with Life Caulk.

As for the rear hatch, was this made to be secured or made to be opened at will? As you can see from the pictures, if I don't seal the rear hatch saltwater will find its way to leak on top of the aluminum fuel tank.

I just dont like how I won't have access to my bilge pumps and float switches as well as not being able to visually see my bilge for water/issues.

What have you all done? Thanks in advance.