Most problems that occur in attempting to base a submarine or submersible aboard a luxury yacht are related to the launch and recovery system. The most common problem is when a potential submarine buyer and owner of an existing yacht discovers that the on-board davit system will not handle the additional weight of the submersible.

A submersible is likely to weigh considerably more than most tenders. In addition, a davit system must be sufficiently sized to handle the weight of entrained water in the main ballast tanks of the sub, snatch loads from the deck rolling and heaving, potential lateral loads, etc., to say nothing of auxiliary capstans or mechanisms to keep the sub from bouncing off the sides of the yacht while being recovered in heavy seas. All this renders the existing davit system on most yachts inadequate for the specialized requirements of the submarine.

The design of a submarine based handling system is a specialized endeavor and an area where we have significant experience and resources allowing us to find elegant solutions to successfully fitting a retrieval system to an existing yacht. Some 15 years ago we orchestrated a design for a system fitted to the swim deck of a 235 ft yacht that held the 10-ton submarine above head level and would swivel down to launch and recover the sub which was firmly held in a set of specialized jaws. The entire package of the sub and the recovery system could be easily placed in a 40-foot container and stored, or shipped to another port, when not required.

Another problem is dealing with a small group of submersibles that cannot be entered or exited while the sub is floating on the surface. In these subs, if the hatch is opened while the sub is on the surface, the submarine will flood and sink. (Better make sure the passenger, who is isolated from the pilot, will not panic and open the hatch). As a consequence, these subs require an ABS man-rated launch and recovery system that are overbuilt, heavy and inordinately expensive. Recently, upon the recommendation of a leading marine scientist a large yacht owner purchased one of these subs only to find out that retrofitting a man-rated system was impossible. More than a million dollars was squandered.

Submarine or submersible integration becomes easier when a new yacht is designed with the launch and retrieval system in mind. For instance, the first Triton 1000 went to the luxury yacht Mine Games and the builder, Trinity Yachts, provided a beautiful davit system that was completely hidden in an integrated box on the aft deck. Push some buttons and the box opens, the davit extends and the sub is elegantly launched and recovered.

While there are a number of differing systems for submarines stored on deck, including davits, winch and slide set-ups, elevator platforms, etc. a common set-up for large submarines is the in-hull storage system. Here, doors on the side of the hull open, the sub drives into an enclosed bay, the door closes and the bay is pumped dry and the sub secured to the inside deck. An elegant system where the long axis of the sub is stored perpendicular to the longitudinal centerline of the yacht is particularly effective and allows for a small external door in the hull that is only slightly wider than the sub's beam.

Shortly at U.S. Submarines we'll begin construction of a specialty diesel electric submarine for a 125 meter yacht that has a special arrangement where the submarine is launched and recovered from under the hull and is completely surreptitious.