Here's one description:
"On the Gulf Coast where my mother raised my five siblings and me, she used to make big bright bowls of gaspachee. The bread was always hardtack, the sea biscuits that resemble giant unsalted saltines. She soaked them in water, squeezed out the excess water and tossed the bread with tomatoes, cucumbers, onions, vinegar, oil and salt. As a child, I thought it was some kind of torture to have to eat bread salad; only now, seen in the golden aura of memory and a better understanding of where I was, does that bread soup/salad seem good to me."
http://seattletimes.nwsource.com/pacificnw/2002/0728/taste.html
Somewhere in my wife's recipe card collection is the recipe, handed down thru the generations from Admiral Semmes himself. (Like all former residents of the Florida panhandle, we have the only ONE TRUE recipe.) The trick is squeezing out the hardtack completely, but without turning it into mush.