Alicia (Marlin Submarines AP6) is a 6-seater submarine

Submarine

A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...

 designed and built by Marlin Submarines of Plymouth, England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

. Designed for research and tourism to depths of up to 305 m (1,000.7 ft), Alicia offers passengers unparalleled views by having a forward section constructed of transparent acrylic spherical sections made by Stanley Plastics.

The submarine is owned by Peter M. Robbins, who founded the Sierra Madre Express. Marlin Submarines is headed by Paul Moorhouse.

Alicia was pressure tested down to 410 m (1,345.1 ft) (required is 375 m (1,230.3 ft)). The budget was US$

United States dollar

The United States dollar , also referred to as the American dollar, is the official currency of the United States of America. It is divided into 100 smaller units called cents or pennies....

1.5 million and the final cost ended at US$2 million. The dive angle is at least partially accomplished with the battery holder of 1750 kg (3,858.1 lb) sliding back and forward on rails.

Visibility

The passenger section of the pressure hull consists of two intersecting transparent acrylic spheres, 1.85 metre inside diameter and 100 mm (3.9 in) 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 Discoveryhttp://www.ussubs.com/submarines/discovery_1000.php3 design concept, also created by Marlin Submarines in 1995, prior to the Alicia's development. Discovery is just 1.44 metre inside diameter to reduce the crane weight. The passenger section of the Alicia, at 1.85 metre inside diameter, has just over twice the volume.

The acrylic sphere, (the viewing area) was produced by Stanley Plastics Ltd, West Sussexhttp://www.stanleyplastics.co.uk.

Diesel-Electric versatility

The diesel-electric configuration of the Alicia 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 S201. The motor will take the full power from the diesel generator set and like S201, drives the prop without the need for a reduction gear.

Vessel status

The Alicia, AP6 prototype successfully completed sea trials in 2004 and is now in the US.

The new P7

Future Marlin Submarines vessels in the series will offer improvements over the original design, whilst retaining the advantages of the Alicia (Marlin Submarines AP6 concept). The new P7 design has 25% more cabin volume without increasing the overall displacement. The spheres are 50 mm (2 in) larger inside diameter and the included angle of the acrylic has been increased. The result is 50 mm (2 in) more headroom and a cabin 200 mm (7.9 in) longer. Subtle changes have also been made to the structure to improve the view even further.

External links

• Marlin Submarines
• Alicia submarine
• NOVA episode about Alicia, "Underwater Dream Machine"
• The Science Channel TV Series, "The Man Who Built His Own Submarine" (2006)
• Recent update on the sub by Paul Moorhouse at the Aquanauts Forums