![]() ![]() The United States military used The Turtle during the Revolutionary War, to middling success. The first military sub, The Turtle, was built in 1776 by David Bushnell and was powered by hand-cranked propellers. Of course, there were no engines at this point, so Drebbel and his 12 oarsmen hit the Thames River and submerged for about three hours. Fast forward about 50 years when a Dutch inventor named Cornelius van Drebbel built the first working submarine. He's basically saying that if you make the boat heavier than the weight of the displaced water, it will sink (purposely). It may be 1570s English, but the concept was undoubtedly that of a submarine. Any magnitude of body that is in the water, having always but one weight, may be made bigger or lesser, then it shall swimme when you would, and sink when you list." A Wet Sub also doesn’t allow occupants to talk normally with each other and share the dive experience."It is possible to make a Ship or Boate that may goe under the water unto the bottome, and so to come up again at your pleasure. ![]() Wet Sub designs do meet the cost objectives but are restricted to use by qualified SCUBA divers and therefore do not provide the ability to offer rides to friends and/or paying passengers. They are too heavy, require specialized air supply equipment and maintenance, and they cost many times more to manufacture due to their complexity. Closed One Atmosphere designs do not meet any of these objectives for the reasons explained previously. To meet this objective, consideration was given not only to the initial purchase price but also to the cost of ongoing maintenance as well as auxiliary equipment required for operation, including launch and recovery. Our hatch solution is free! A good quality sealed submarine hatch could easily cost as much as an entire SportSub.Īnother primary objective of the SportSub design is to keep the cost low enough for personal recreational use and for profitable tourist ride operations. It also allows owners of smaller boats to enjoy the advantages of taking their own submersible wherever they go.Īnother benefit of the open hatch approach is cost. This fact is particularly critical when a boat is designed specifically to carry a sub and passengers to a dive site in a tourist operation. What this means is that a significantly larger boat would be required to carry, launch, and recover the sub if it weighed more. ![]() The added weight carried by the boat would probably double. If it did weigh one thousand pounds more, the weight of a davit to launch and recover it from a boat deck may also weigh a thousand pounds more. If the sub had twice the internal air volume it would weigh about one thousand pounds more. This in turn increases the weight and cost of the handling equipment. This is not possible with a One Atmosphere design so they are inevitably heavier.Īdded weight increases the required strength of all handling equipment. The SportSub design provides a very small internal air chamber because the occupants are half submerged in water. If the internal air volume can be reduced, the weight can be reduced. The weight of a sub must always be exactly equal to its buoyancy, most of which comes from the air inside it. The weight of any dry submersible is dictated by its internal air volume. The system also makes underwater adventures more available to passengers who might otherwise feel uncomfortable in an enclosed space. This gives the operator more confidence that passengers will be capable of handling a ‘worst case’ emergency situation. Having to enter the sub by swimming into the cockpit is a nice way to help prevent passengers from taking a ride if they aren’t comfortable under water. The SportSub design eliminates this problem.Ī third safety feature of the swimming entry is that operators and occupants are more confident. If a hatch in at the top of the cockpit in a closed system were to leak, all the air would escape and buoyancy would be lost. Since the SportSub works in a balanced pressure system, the hull isn’t required to contain enormous pressure and can never be crushed by external water pressure. Occupants can readily escape from the SportSub by swimming out. The simple rear opening can never get stuck or jammed shut, trapping occupants inside. The greatest advantage of swim-entry is safety. ![]()
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