Tony might be able to give you some ideals on how to keep it in the boat.
Sorry Tony couldn't resist.
I think I would use some plastic to make some corners for it and maybe a strip along front and back. That should keep it in place with a little water when not in use. When I had my Bluewave built I gave them a footprint of my 50gal Grayline. They made a plastic ring on the floor for it to set in(about a 1/2" high). The ring keeps it from moving around and few inches of water in it, if just transporting without any bait.
I don't believe in Miracles, I rely on them.
YETI Pro staff,
Pro Staff Baitbuster Cast nets 1.5lbs per foot and six panel