Sand sucks. Try and pick a spot where its not as deep. The mesh thing is great, but like Janice stays, you often don't have enough. I have resorted to gyros even with dilaog on some occasions because the wind was so bad. Most sound mixers are fine with this (I always tell them first). One, it's a big open space. Two, gyros put out a sound at a frequency that is fairly easy to minimize in the mixing. Three) Joke with the sound guy "that its better than a sideways frame".
Of course fatigue is a real factor because your legs will get tired much faster fighting the sand so minimize the weight and extend the monitor and batteries (if your sled does this) out as much as possible to gain back some of that inertia (likewise build your camera accordingly - less weight but put the accessories where they increase pan inertia). Keep the gimbal as high to the camera stage as possible to minimize roll.
PS, while barefoot may feel awesome in the sand, be CARFUL! As stated, you will sink deep… right into that hidden piece of glass, nail, etc. I'd avoid this temptation and wear good sneakers.