Here is what I made. I do not like things installed in my little ISUZU truck other than my flush hardtop.
Well I have to haul a lot of gear around the island and carry it on a 18' Zodiac so I used some scrap wood and made this.
It works great for Al80's and Al100's.
It is light and I can store the tanks in the racks in the garage stacked up using less room and no chance of them falling. The cutouts are 1" plywood. The base is 3/4" plywood and the pieces are glued and screwed together to make a strong bond. I use a cheap tie down strap that I use to secure the Zodiac to its trailer.
The cutouts are the size for the 80's but with the scrap garden hose the 100's fit fine. The hose is better than felt or other material as it grips the tanks, does not hold moisture and does not scrape the tank. My only expense was the 2 eye screws that are attached on two of the cutouts from the tank rack and a tube of Shoe Goo to attach the hose for each cutout. Did not want screws hitting the tanks. I had all the other materials laying around the garage waiting to think up a project.
I put hose on the bottom to keep the movement on the boat down so it would not damage the floor. I attached this with three screws per section. On the boat I can stack 3 more tanks on top if needed but normally I just put another rack in the boat. You can rig up your BC or wing and lay them back in the rack for the trip out to the site. Your 2nd tank is right beside. This cuts down on the use of space that is limited. I normally dive alone or with 3 dive buddy's. Fits just right for us. I do not like clutter or things bouncing around on the boat as it is a balloon and do not want to poke holes in it.
Not movement even if you do not put on the strap.
Just my little contribution to my diving experience.....