Season the flour with 1 teaspoon of salt and 1/2 teaspoon of pepper. Coat the crabs with flour and shake off excess. Heat butter and oil in a large skillet. When hot, add the crabs, shell side down first and saute for about 3 to 4 minutes a side (stand back a bit from skillet as crab will pop and splatter as you saute them.)
Remove the crabs and keep them warm. Add lime zest, juice and water to the pan. Deglaze the pan by scraping up all the browned particles with a wooden spoon and incorporating them into the lime juice. Season to taste with salt and pepper. Boil the juices down until syrupy. Set crabs on warmed dinner plates and pour pan juices over them. For fancier occasions, garnish the plate with lemon rounds and sprinkle toasted almonds over the crabs.