Fish stock (food) Fish stock (food) Fish stock forms the basis of many dishes, particularly fish soups and sauces. In the West, it is usually made with fish bones and fish heads and finely chopped mirepoix. This fish stock should be cooked for 20–25 minutes—cooking any longer spoils the flavour. Concentrated fish stock is called "fish fumet". In Japan, a fish and kelp stock called dashi is made by briefly (3–5 minutes) cooking skipjack tuna (bonito) flakes called "katsuobushi" in nearly boiling water. Other Japanese fish stock is made from fish that have been fried and boiled for several hours, creating a white
Skipjack-class submarine from the s that preceded the "Skipjack"s. Unlike the "Skate"s, this new design was maximized for underwater speed by fully streamlining the hull like a blimp. This required a single screw aft of the rudders and stern planes. Adoption of a single screw was a matter of considerable debate and analysis within the Navy, as two shafts offered redundancy and improved maneuverability. The so-called "body-of-revolution hull" reduced her surface sea-keeping, but was essential for underwater performance. Also like "Albacore", the "Skipjack"s used HY-80 high-strength steel, with a yield strength of , although this was not initially used to increase the