Ha! Your on the wrong forum with a question like that!
nice find!
If we were all honest, and were hunting as hard as you have been, beach hunters have at least once experimented "swinging both ways"...for purely pain avoidance reasons of course!
That said, I learned a good trick working that big expansive sand like you are in...instead of swinging the arm, I swing the whole body...imagine a crouch, slight bend at the knees. swaying side to side at the hips and letting steady momentum propel the coil..little to no arm movement at the elbow, more like guiding the weight of the coil than powering it...almost a 270 degree swath, nearly 4 meters arc...really lets me cover a lot of sand with no pain in any localized portion..just an overall complete workout....
In the water, instead of swinging side to side, I work a "herringbone" pattern...that is to say, I sort of push and pull the coil in sort of a wide "V" out in front of myself...using my body weight and legs to propel the coil out, pull it back in, reverse sides, still swaying at the hips, and driving off my legs..push it out, pull it back in, rock and repeat....and so on and so forth, not fighting the water resistance...nice and steady....probably looks stupid, but who cares? NO PAIN, and huge coverage!.
An elbow just cannot take the strain of a traditional swing in your hunting circumstances for very long...but the complete body (especially the legs) can...you'll get it right away if you try it, you being a danged old circus performer and all...I've not seen a youtube vid that describes this...but you will get it with a little practice just out of avoiding pain if for nothing else.
My digging arm does get a little tender at the shoulder, but its on account I have that crappy homemade icecream scoop, and I'm pulling heavy gold all the time with it!
Mud