The F90M Gundam F90 Marine Type is one of the many mission packs developed for the F90 Gundam F90 by the Strategic Naval Research Institute. The Gundam F90 Marine Type is designed for underwater combat. The M-Type's backpack is equipped with thermonuclear hydrojets for underwater mobility. Due to improvements in armor material and reactor output compared to previous generation mobile suits, it is able to reach a maximum depth of 400 m and has a maximum diving speed of 90 knots. It is armed with several topedoes, an arrow shooter, and a heat combat knife for close combat. It also has the Freezy Yard gel, first used by the Gogg, to defend against naval mines, as well as a searchlight on the right shoulder and a snorkel camera on the left.
The F90 M-Type was completed along with the A, D, S, H type options in September, U.C. 0111. It was the first aquatic mobile suit design used by the Federation since the RAG-79 Aqua GM series decades ago.