I am working on a 88 Chris Craft stinger. My fuel tanks from the factory are held in with foam which is now water logged, so I am digging it all out and pulling the tanks. Is there a better way of securing them in? I have been told that this is a pretty standard method to hold them in, I am not crazy about it after seeing how much water I was holding. Is it possible to use some PVC boards or similar to support it? I would prefer a method that would at least allow the water to have somewhere to drain to. The way this was done, any water that got under the floor was there to stay. Any advise is appreciated!

Following as i pulled all the foam and fuel tank out of my wellcraft nova last fall and would like to put it back in this summer.

I think Tim Sharkey from sharkey image locked his tank in with custom L angle bracket he made out of fiberglass
go check his facebook page and scroll down!

Tim sharkey made L angle out of fiberglass to hold them down
you might want to scroll down his fb page !

just foam it in w/ closed cell.it won't hold water.

Thats how I did it.. still holding great.
I put large thick rubber pieces where they contact the bottom.

I just finished replacing the fuel tank on my '86 Panther. Was also thinking of an alternative to foam. Then decided in another 39 years that I would be dead the next time the tank needed to come out. I went with 2lb closed cell foam. I did drill a couple of holes in the bottom of the PVC pipe that runs down the inner keel.
I have a little write up starting at post 201.
Scarab Panther always a work in progress

Lots of options..
Closed cell foam which will stay dry for years, but will inevitably get wet.. water can pass through the cell membrane over time which will fill the foam with water and then it takes just as long for it to get back out.. What I've done and lots of other people have done is just lay adhesive backed rubber weather stripping along the hull for the tank to sit on but will still allow water to drain and then you use whatever you want to secure the sides (foam, rubbers, angle iron, pool noodles, whatever)...

Many years ago, I re-foamed the fuel tank on my old Chaparral. Don't remember what type of foam I used, but I do remember it was a 2-part mix.
Careful pouring new foam. That stuff expands and if it has nowhere to go, it can move bulkheads.