Fleet Problem XX

Fleet problem was the term used by the United States Navy to describe each of 21 large-scale naval exercises conducted between 1923 and 1940. They are labeled with Roman numerals, from Fleet Problem I through Fleet Problem XXI. A 22nd Fleet Problem exercise, scheduled for 1941, was canceled because of World War II.

The fleet problems were usually once a year exercises in which U.S. naval forces would engage in mock battles. One or more of the forces would play the part of a European or Asian navy. They were the culmination of the Navy's annual training maneuvers.

Fleet Problem I was held in February and March 1923 and was staged off the coast of Panama. The attacking Black force, using battleships to represent aircraft carriers, tested the defenses of the Panama Canal. A single plane launched from Oklahoma—representing a carrier air group—dropped 10 miniature bombs and theoretically "destroyed" the spillway of the Gatun Dam.

Fleet Problems II, III, and IV were held concurrently in January and February 1924 took place in the Caribbean and simulated actions that might occur in the Pacific.

Fleet Problem II simulated the first leg of a westward advance across the Pacific.

This exercise focused on a defense of the Panama Canal from the Caribbean side. The Blue force was defending the canal from an attack from the Caribbean by the Black force, operating from an advance base in the Azores. It was to practice amphibious landing techniques and the rapidity of transiting a fleet through the canal from the Pacific side.

In the exercise, a Black force special operations action resulted in the "sinking" of Blue force battleship New York in the Culebra Cut which would have blocked the canal.

This problem simulated the movement from a main base in the western Pacific to the Japanese home islands—represented in that case by islands, cities, and countries surrounding the Caribbean.

Fleet Problem V was held in March and April 1925 and simulated an attack on Hawaii. The Black force, the aggressor, was given the United States' first aircraft carrier, Langley along with two seaplane tenders and other ships outfitted with aircraft, while the defending Blue force had no carriers. In addition, aircraft aboard the battleship Wyoming could not be launched for lack of a working catapult. Langley's positive performance helped speed the completion of aircraft carriers Lexington and Saratoga.

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