AP6

Built under American Bureau of Shipping survey to obtain +A1 Submersible classification, the Marlin Submarines AP6 is a 6-7 person, 19.4 tonne tourist submarine capable of diving to 305 metres. This vehicle would make an excellent tourist submarine offering a premium deep dive experience with an earning potential of over US $1,200 per hour. Many excellent sites round the world are available which to base a potentially profitable and compact operation.

The passenger section of the pressure hull consists of two intersecting transparent acrylic spheres, 1.85 metres inside diameter and 100mm thick. The passengers and crew are treated to a spectacular all round view previously enjoyed only from the most advanced research submersibles.

The vessel is the first ever to employ this twin sphere geometry. The craft is a 30% larger version of the US Submarines Discovery design concept, also created by Marlin Submarines in 1995, prior to the AP6 development. Discovery has an inside diameter of just 1.44 metres to reduce the crane weight. The passenger section of AP6 has just over twice the volume with an inside diametre of 1.85 metres.

The Diesel-Electric configuration of the AP6 allows the submarine to be placed on station at the dive site relatively rapidly, without the need for a large towing vessel and without eating into battery reserves. In addition it is possible to charge the air banks (used to "blow" the main ballast tanks) when under way on the surface, saving on maintenance time at the dock. Charging the main battery using the Diesel engine to drive the main motor as a generator is also possible. The next generation will use the same rare-earth motor technology as 201. The motor will take the full power from the diesel generator set and like 201, drives the prop without the need for a reduction gear.

Future Marlin Submarines vessels in the series will offer improvements over the original design, whilst retaining the advantages of the Marlin Submarines AP6 concept. The new P7 design has 25% more cabin volume without increasing the overall displacement. The spheres are 50mm larger inside diameter and the included angle of the acrylic has been increased. The result is 50mm more headroom and a cabin 200mm longer. Subtle changes have also been made to the structure to improve the view even further.