Abstract: An unmanned underwater vehicle having one, some, or all of an integrated communication control fin, a ballast and trim control, a reusable trigger mechanism for a drop weight, and a visual hull display. Furthermore, associated methods are also provided.

Abstract: An unmanned underwater vehicle having one, some, or all of an integrated communication control fin, a ballast and trim control, a reusable trigger mechanism for a drop weight, and a visual hull display. Furthermore, associated methods are also provided.

Abstract: A knife-and-sheath combination includes a knife with a blade having two opposing broad faces and an opening through the blade extending between the broad faces, and a handle extending from the blade. The combination also includes a sheath including a sheath body having a receptacle sized to receive the blade therein, and a positive lock operable to lock the knife to the sheath. The positive lock includes a locking element engagable to the opening in the blade of the knife, and a lock release accessible to a user of the knife-and-sheath combination, the lock release being operable to disengage the locking element from the opening in the blade of the knife.

Abstract: A knife comprises a handle, a blade having a blade back, and a hook integral with the blade. The hook includes a hook body extending laterally outwardly from the blade back side of the knife blade. A finger of substantially constant diameter and with no sharp edges extends rearwardly toward the handle from the outward margin of the hook body. The finger preferably has a length of at least about 0.2 inches and is displaced laterally outwardly from the adjacent portion of the knife back by a distance of at least about 1/4 inch. The finger is oriented at an angle to the handle of at least about 5 degrees. A slot defined by the hook body, the finger, and a portion of the blade back includes a straight cutting edge oriented at 90 degrees to the finger, and centering ramps that guide the material being cut into the cutting edge.

Abstract: A compass housing capable of withstanding high external pressure such as encountered in deep submergence applications. The housing includes a pair of hemispherical portions interconnected to form a sealed enclosure and at least one portion being formed of a resilient material capable of expansion and contraction in the presence of varying differential pressure conditions. The housing is completely filled with a damping liquid under pressure to provide an internal pressure higher than atmospheric pressure such that in the presence of higher external pressures, the inner and outer pressures tend to equalize, thereby minimizing the differential pressure on the housing itself.