Minisub Specs

Nelson Institute of Marine Research

Santa Barbara, California


The MiniSub was the first specialized vehicle designed for the SSRN Seaview. The MiniSub is a two man vehicle. They sit in a cockpit similar to an airplane. Up front there is a retractable laser in front of the sonar housing. Just fore of the canopy there forward control fins. One on either side of the sub. Just fore of the control fins are forward observation lamps. There is a communications antenna array aft of the canopy. There also is an aft sonar array below the propellor and rudder.

The MiniSub is capable of maneuvering in 3 dimensions. Power is applied to two battery powered electric motors, mounted amidships, one on each side of the sub. The speed of each motor is controlled independently by two speed control levers in the dashboard. These motors normally propel the sub forward, but can be rotated as much as 90 degrees upward to propel the sub up or 90degrees downward to propel the sub down. Turns are accomplished by speeding one motor up and slowing the other down. The sub can turn on the spot by putting one motor in full reverse and the other in full forward. The MiniSub maneuvers much like a helicopter except that it can not fly sideways. Piloting a MiniSub is a new and exciting experience. While a car operates in 2 dimensions, the sub operates in 3. This extra dimension takes a little getting used to, and definitely adds more than a little excitement. The top speed of 24 knots doesn't sound very fast to those of us used to driving down the highway at 65 mph, but remember that while doing 65 you can see along way ahead of your vehicle. Just imagine operating an airplane or helicopter in a blizzard where the visibility is limited to 20 - 50 feet. Yes it would be exciting, but it would also be suicidal. When underwater, 24 knots is more than enough speed.


In the event you do have a problem the MiniSub has a number of safety backup systems....

  • Upward Thrust : To power yourself to the surface.
  • Buoyancy Control Adjustment for Positive Cockpit Buoyancy: Allows you to perform a controlled ascent under the control of the buoyancy control system even if you have no battery power left.
  • EBC Manual Override This allows you to override the sensing mechanism of the EBC in the event of a sensing mechanism failure.
  • Manual Cockpit Air Inlet: This system uses air from the Reserve air tank and allows you to bring the sub to the surface in an out-of-air situation, in the event of an EBC failure, in the event of an electrical failure, or all of these at the same time. This system's lever can also act as an "emergency surfacing switch" allowing either the pilot or passenger to bring the sub to the surface in the event of a problem.
  • Dropable Lead Ballast: 20 of these 10 pound lead bars allow you to trim the weight of the sub to accommodate exceptionally light or heavy people or loads. They can also be thrown out of the sub to create positive buoyancy in an emergency so the sub can ascend to the surface under the control of the buoyancy control system, even after a total loss of electrical power or Reserveair.
  • Spare Air: Spare Air is a small hand held compressed air cylinder with a mouth piece that allows you to create positive buoyancy, or to swim away from the sub to the surface. There is a Spare Air tank for both persons in each sub.
  • Front and Rear Ballast Tanks: By blowing ballast from these tanks, the sub will ascend to the surface, however, it will not be under the control of the buoyancy control system. You must have compressed air left to blow ballast with. This system will, however, assure positive buoyancy when you reach the surface.
  • Easy Exit at any Time: Since the MiniSub can be exited safely at any time, a free swimming ascent to the surface could be performed safely from any depth the sub is designed to normally operate in.
  • Onboard Emergency Equipment: In addition to Spare Air cylinders, each MiniSub carries a mask and inflatable personal flotation device for each occupant, and an emergency signaling kit that can be removed with the occupants should an emergency ascent to the surface be required.
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