The "Sigsbee Deep" is the deepest point of which body of water?

The "Sigsbee Deep" is a roughly triangular basin that is the deepest part of the Gulf of Mexico named after Commander Charles Dwight Sigsbee (1845 – 1923). In US history he is known as the captain of the U.S.S. Maine that was sunk in Havana Harbour in 1898 triggering the Spanish - American War.

In the 1870s, Sigsbee led the first expedition to chart the Gulf floor and his name is given to several features. These features of the Gulf are within the deepest of the 300 mile (482 km) wide patch known as the "Sigsbee Basin" or "Sigsbee Deep". The basin is centred about halfway between the coast of Texas and the Yucatan Peninsula. It sits on top of vast beds of salt. It may have formed when the beds subsided several hundred million years ago.

The basin is surrounded by sharp cliffs on 3 sides. The cliff on the northwestern side is the "Sigsbee Escarpment" which is up to 4,000 feet (1219 m) tall. The centre of the basin consists of the "Sigsbee Abyssal Plain" whose smooth surface is broken only by a few salt domes, the "Sigsbee Knolls". The "Sigsbee Basin" is relatively unexplored and different sources record its maximum depth between 12,300 feet (3749 m) and 14,400 feet (4389 m).

Recent work has shown that the basin is home to the most persistent current in the deep Gulf of Mexico. The rotating current moves at about a tenth of a mile per hour (283 km per hr), and it has a familiar name namely the "Sigsbee Abyssal Gyre".