What is the one thing the run out in fort repose and how will this be used? chapter 12

The salt problem is solved when they go back and read the diary of Randy's ancestor, who founded Fort Repose; in it, he writes about Blue Crab Run, a place downriver with a pool full of blue crabs and a beach made entirely of fine white salt. Five boats of thirteen men head down the river to find this place the very next morning.