lower back support

I need some lower back support for my Eddyline Nighthawk. Been solving the problem with those arm float things my grandkids use & putting it just in the center of my lower back. It works but jusr wondering in anyone has come up with a better solution.

In fact,
the foam floatation noodle is what the ergonomics experts recommend.

NSI Backband
I had one of these and loved it…

http://www.northshoreinc.com/anatomcbb.html