We camp on the outer beaches and unfortunately there are the macho types who muscle through everything and tear up the on off ramps without airing down. This turns the ramps into quick sand. Coupled with campers on either side of the on ramp so you cannot carry much speed one can sink quickly. The simple lesson is to stop as soon as you've lost traction and dig yourself deeper. A year ago I got caught in it and had to unhitch to drive truck out of the sink hole, fill it in then hitch up again. Jacked up the tt wheels and filled that in also, then used the shovel to create a path for the tt tires and away we went. In the mud like the picture I would probably use a plank under the tire and would have gone backwards to the road. If it didnt move I would have had someone pull the tt backwards while I pushed. SUX getting stuck but youll soon find out who your neighbors are..