I believe the Box Crab is a type of a King Crab with shorter legs. I would imagine they are pretty good eating.
I used to scuba dive and dove various places in the Puget Sound and on the Oregon coast. The best of all was in the San Juan Islands where there was abalone. There were some places also that had big Scallops. It is cold, but wearing a suit makes that all seem so warm.
Have you ever jumped in the water in the summer? Even then it is still so cold. I hear that people swim in Vancouver comfortably in the summer as the water up there gets to about 70 from a different current.