Steven, I hunt in the surf on a regular basis... I don't use a harness. Typically, my Minelab Excal is strapped to my right arm and my Stavr scoop, with a carbon fiber handle, is in my left hand. If your scoop is not too wide and heavy, but has large drainage holes, you will have no problem working it with one hand.
When I'm out in the surf I allow the retreating wave to clear the sand from the scoop basket, leaving only the target behind. If I'm working the surfline, I'll dump the sand from the scoop just above water level, rescan, and retrieve the target. This technique is very efficien