Leaving access holes in the floor...

[Tyania]

Can people show me how they have done their floors to keep the access panels in the floor accessible?
I have a just-over-5-inch hole in the floor for accessing the gas tank. And at the front center, I have an odd shaped access panel in the floor to access the transmission. I would like an elegant way to keep access but also have the area sealed so that water cannot get up into the floor.
For the round one something like this would be ideal except that it does not have a collar to seal to the metal floor through the 2" of flooring, subfloor, and insulation.
https://www.campingworld.com/access-hatch-5-inch
All ideas much appreciated... even better with links or photos.
Thanks

[roach711]

The hatch over my gas tank originally had a square piece of aluminum screwed to the floor and I left it in place when I added insulation and a new sub floor over it. I cut an access hole in the new sub floor then made an oak cover for the hole. It's under the bed otherwise it would be a trip hazard.

The marine hatch you linked would work fine to keep out water. I have one of those on my water tank and it seals fine.

[Dharmabum]

We just used the foam board we cut to plug and the plywood we cut to fill it with. Along with the original metal plate that was there originally. Also completely sealed the plug(s) with metal tape. Air tight and insulated, but easy to get at if ever needed.