"Immediately after the Second World war, the US Navy began development of a family of general purpose torpedoes. One of these was the Mark 37, developed originally as a submarine defensive weapon/decoy against ASW ships, although the decoy element was later dropped. Development also continued as an ASW weapon to be launched from surface ships. It entered service from 1956 and was purchased by at least 16 navies. During the 1960s, it was reported that in certain conditions Mark 37 torpedoes would arm themselves. US Navy documents released in late 1993 reportedly indicate a jettisoned, torpedo which turned full circle, was responsible for the loss of the USS Scorpion (SSN 589).

The Mark 37 was also used as a basis for the Mark 67 mobile mine with a new warhead. This weapon is still being marketed.

Improved Soviet submarines rendered the Mark 37 increasingly obsolete and in 1968, the Northrop Corporation's Ventura Division and the US Navy began an upgrading programme. This involved replacing the electric propulsion system with an Otto-fuel system similar to that used in the Mark 46, as well as providing significant improvements in guidance and control. The new weapon was designated NT-37; development was completed in 1973.

The original production version was NT-37C, which was followed, in the late 1970s by NT-37D and in the 1980s by NT-37E. The NT-37 is available either as a new build or as a new weapon. Late in 1979, Honeywell (now Alliant Tech Systems) purchased responsibility for the weapon and its development from Northrop and in 1993 marketed NT-37F as Seahuntor (Sea Hunting Torpedo), which began development in 1992.

It is reported that South Korea is developing a heavyweight multirole torpedo, White Shark, based on the NT-37 body and that a prototype appeared in 1977.

The versions of the Mark 37 are:
Mod O: Submarine launched free running torpedo.
Mod 1: Wire guided anti-submarine torpedo for surface ships.
Mod 2: Updated Mod 1.
Mod 3: Updated Mod 0.

The Mods 0 and 3 are free running torpedoes which are launched on are target interception course which is maintained until, at a preset range, it initiates a process which arms the warhead and switches in the attack logic circuits. The Mods 1 and 2 were launched towards the target, which was detected by sonar and then guided close enough for the seeker to acquire the target itself. Acquisition takes place at a distance of 215m."