A Plymouth submarine firm is to take tourists to the depths around the South West's coastline.

Submarine trips for tourists are already available in exotic locations such as the Caribbean.

But the market for such trips around the UK coast remains unexplored.

Marlin Submarines is building a �750,000 vessel to carry six passengers at depths of up to 160 feet.

The UK does not compare with the Cayman Islands or the Bahamas, but it is usable

Paul Moorhouse, Marlin Submarines

Operating from Plymouth or Dartmouth, the submarine will take people on hour-long dives to the most popular wreck sites.

Paul Moorhouse of Marlin said the submarine could go to greater depths than divers.

He said there were more than 20 wrecks within an hour and a half from Dartmouth.

And the quality of Britain's seawater should not put potential passengers off.

He said: "The south coast has some very good visibility.

Marine life

"There are plenty of places in the tropics that are not as clear.

"It does not compare with the Cayman Islands or the Bahamas, but it is usable.

"There is a surprising amount of marine life around the UK."

The sub will offer a panoramic view

The submarine, sponsored by an American businessman, is the world's first twin-sphere submarine, using two giant acrylic bubbles sandwiched together to give the passengers an all-round view of the seabed.

Providing it gets a marine safety certificate, the first submarine could be exploring the depths by June next year.

The only submarine accessible to tourists in the region before now was the hulk of the disused boat HMS Courageous in Devonport dockyard.

Mr Moorhouse expects the new submarine to be aimed at a niche market of divers and others interested in the technology.