Here's one I made on a CNC router.
I was thinking about cutting a couple more pieces that attach as a base to allow it to safely stand vertical, but haven't decided yet. Cost was a 6 ft 1" x 8" solid oak board, some Kregg screws and four strip of thin craft foam. Still have to attach a couple hose anchors.
Built this several years ago.
Sits vertical for shop use. Lays flat for transport. Pool noodles cushions tip overs. (Been tested) handle can be removed for removal for filling by local dive shop.