Although real crab cakes originated in the Chesapeake Bay, you can make them with the Dungeness crab of Northern California if you want to!
Crush crackers with a heavy rolling pin until in fine crumbs, about 1 cup. Place in a layer on a sheet pan or on a work surface.
Combine remaining ingredients except for butter. Divide fish mixture into 4 equal parts. Form each part into a cake about 3-1/2 inches in diameter and 3/4 inch thick. Plop each cake down into crumbs. Pat crumbs all over so that all exposed surfaces are covered.
Melt half the butter in a small nonstick skillet just large enough to hold 2 cakes. With a pancake turner or large spatula, gently transfer to crumb-covered cakes to skillet. Cook over medium heat for 6 minutes. Turn with a spatula and cook for 6 minutes more. Surfaces should be nicely browned; if they start to get too brown, reduce heat. Repeat with the remaining butter and crab or fish cakes. (Serve by themselves or with wedges of lemon or homemade Tartar Sauce or Louis Dressing.)
Note: A nice addition would be kernels of fresh corn or chopped red pepper. (Tartar sauce is mayonnaise with hard-boiled eggs, capers, pickles, shallots, parsley and tarragon added. Louis dressing is mayonnaise with ketchup, pickles, shallot, grated horseradish and tabasco added.)