Abstract: A method for improving the accuracy of an inertial navigation system (INS) by performing a synchronization procedure to align the INS to a compass-derived initial heading comprises the steps of determining a heading of minimal error for the compass and defining that heading as the initial heading; orienting the INS to align with the so-defined initial heading; synchronizing the internal navigation system to that heading; and proceeding with navigation by use of the INS. The INS may be vehicle mounted or be contained in a portable navigation unit for swimmers or other users. The heading of minimal error may be determined by placing the compass within a multi-axis Helmholz coil system and monitoring compass readings and deviation errors as a function of actual compass positions.

Abstract: A shock-mitigating damper apparatus for vertical shocks has a scissor linkage extending vertically between a base and an object. A damper is also connected between the base, the object, and is mounted to the base for substantially horizontal reciprocating damper motion. An articulated arm assembly connects one end of the damper to the object at a point substantially in vertical alignment with an intermediate pivot point for the scissors.

Abstract: A sealable engine containment assembly provides a waterproof environment for an internal combustion engine and ancillary equipment, thus performing a “engine room” in a sealable container. The container includes an air inlet port for passage of air from the container exterior, and an exit port for passage of engine exhaust to the container's exterior. Both the inlet and exhaust ports have valves to isolate the port from the container exterior when the engine is not operating. A waterproof coupling for transmission of engine drive shaft output may be provided, along with waterproof couplings for electrical, hydraulic and fuel lines. The engine assembly is of utility in open-hull submersible vessels as well as for use in other environments where potential water ingress could prove deleterious to conventional internal engine assemblies.

Abstract: A personal support device having particular utility for use by personnel in high-performance surface watercraft comprises a bolster adapted and dimensioned to support an occupant for shock isolation from accelerations experienced by the vessel. The bolster is mounted by pivot means extending between the bolster and a back plate which is rigidly mounted to the vessel. The pivot means permit the bolster to pivot in an arc with respect to the back plate. A shock absorber extends between the back plate and bolster to dampen the accelerations which would otherwise be passed to the bolster by the pivot means from the back plate. The bolster is capable of supporting a user in a standing position or receiving a seat assembly to allow an occupant to be seated.

Abstract: A submersible surface-planing vessel has the capability to operate with a lowered profile on surface propulsion to lessen the visibility of the vessel, and sink to the bottom for temporary storage, followed by resurfacing and dewatering to operate as a planing craft. Surface propulsion is provided by an engine system which can be totally sealed when the vessel submerges. A buoyancy system, which may include both open and closed ballast tanks, permit the vessel to sink, refloat or to be of neutral buoyancy as required. The vessel is constructed to maintain the center of buoyancy above the vessel's center of gravity irrespective of the degree of fill of the ballast tanks to maintain the vessel in an upright orientation at all times when under water and transitioning between surface and submerged states.

Abstract: A self-propelled underwater transport vehicle provides propulsion for one or more divers to allow submerged travel over extended distances. The vehicle has a cylindrical open hull supporting a deck upon which a diver is supported in a prone position. A blunt bow extends upwardly from the front of the hull, and develops a flow shadow in which the diver is positioned. A control yoke, operable by the diver, is connected to steering elements, which may include bow planes and a pivoting thruster. The cylindrical hull allows the vehicle to closely approach objects without contact therewith, while the flow shadow developed by the bow minimizes drag, despite the open structure of the vehicle.

Abstract: An active shock-absorbing boat seat system has a seat system mounted to the boat deck through an active shock absorber. Sensors monitor both the shock to be passed from the deck to the seat as well as the shock actually received by the seat after passing through the shock absorbing system. A controller monitors the shock levels and provides a continuing control signal to the shock-absorbing unit to control the response of the shock-absorbing unit during the duration of the shock. The control system can provide for adjustment of various operating parameters for the system, including initial position of the seating system, overall ride stiffness, maximum allowable shock, and other parameters.

Abstract: A seating system especially well adapted for use in high-speed and high-performance water craft provides improved support for a user, in both standing and sitting positions. The seating system includes a fixed base upon which is mounted a frame positionable and lockable in a chosen forward/aft position. The frame supports independent backrest and seat units, each of which is independently vertically positionable along the frame. The seat unit further includes bolster and seat portions which are pivotable between a first position in which the seat portion is operative and a second position in which the seat portion hangs downwardly, in an inoperative orientation, and where the bolster provides support for the standing occupant.

Abstract: An improved boat seat includes an adjustable footrest and an integral steering control mounted to an armrest. The footrest is height-adjustable, and is pivotable between operative and retracted positions at any chosen height. The steering control is mounted to the distal end of the armrest, and is at least partially embraced and covered by an armrest pad.

Abstract: A seating system especially well adapted for use in high-speed and high-performance water craft provides improved support for a user, in both standing and sitting positions. The seating system includes a fixed base upon which is mounted a frame positionable and lockable in a chosen forward/aft position. The frame supports independent backrest and seat units, each of which is independently vertically positionable along the frame. The seat unit further includes bolster and seat portions which are pivotable between a first position in which the seat portion is operative and a second position in which the seat portion hangs downwardly, in an inoperative orientation, and where the bolster provides support for the standing occupant.