The deck pipe has screws sticking into the cabin about 1.5" the drain tile goes around then and is compressed to fit. there is a 3" hole in the shelf. on mine (83) the top locker feeds into the locker under the bunks in the cuddy. i carry about 250' 1/2 anchor line(rode to you nautical wheelers) with 30 ft of chain. i hate coming back and the anchor has been dragging.
this is a 3 step ladder that helps a lot that is a tank rack i made out of 2 two liter coke crates on plywood with a piece of rubber on the bottom. works greeat and holds 4 tanks with bc's
this is a tank holder system that holds a 80 cf tank upright. i have four of them onboard

shots of the anchor lockers
inside of the connecting tube