The ULTRAMARINE is an amphibious knife, carried around from underwater operation equipment (diving suit) to ground operation equipment (tactical vest). Two different versatile sheaths were therefore developed for it. The scuba sheath can be worn at the ankle, or its hard ABS section can be attached by two BELT-CLIPS to either the breathing apparatus or BCD belts. The land sheath (OPTIONAL, included on request) is MOLLE system compatible, designed to be attached to the tactical vest and carried inside a waterproof bag during underwater operations. All an operative has to do, if getting rid of his diving suit after landing, is to draw the knife from its ankle sheath and place it in the tactical vest sheath. Primary functions: field operations, underwater operations, emergency tool, survival and combat.