When the sweetest surfing or fishing spots are way the hell down a long (vehicles-allowed) beach, do like ranger Wouter Ketel, of North Carolina's Cape Lookout National Seashore (and don't, like, forget to check the tides):
(1) Take a 4x4 with good CLEARANCE.
(2) Mud and snow tires dig into sand; radials float. Drop them to 18 or 20 psi for better TRACTION.
(3) When you hit a soft section, don't stop; use your MOMENTUM or a slow acceleration to get through. And try not to make quick turns.
(4) If you start to sink, don't spin your wheels—you'll go deeper. DIG the sand away, lower pressure a bit more, and jam a board under a tire for grip—but keep in mind the possibility of said board hurtling toward yon innocent bystanders.