I've put on a whole harness before for groundfishing... After a couple hours pounding the bottom, we'll be in lazy fishing form, rods in holders, clams & 20 ounce sinkers bounching off the bottom. If I'm too late on the set a couple times, I'll strap the harness on and just kick back - now I can set the hook & drink a beer at the same time
They make those "sea cups" for next to nothing - sold at boat US; just a cup for the rod butt that slips into a regular belt, it gives you something to brace on.. Or, for a light weight belt, there's a bunch out there in the $30 range that would be an improvement.
I've got the BOATUS harness & belt setup.. It's just a starter setup, and I think immeadiatly after my first shark I'll be upgrading the belt to a Braid brute buster.. The harness I'll probably stick with. I think the style belt that doesn't brace on you legs, like the BOATUS I have, is probably only safe for females, if you get the drift...