Mercury uses methods which have worked since the last century.

Mercury uses a method of recovering the cable utilised since the late 1800s when the first cable was laid on the floor of the Atlantic Ocean.

Rope, stretching miles long, is attached to a grapnel hook which is dragged along the ocean bottom to find the cable. It is then hauled up to the ship and repairs are made.

New commander of the cableship Captain Bert Porter said: "The only thing that has really changed is the cable itself.'' Today the inch thick Private Transatlantic Telecommunications system links Bermuda to the United States and the United Kingdom. Its submarine fibre optic cable can accommodate over 17,000 simultaneous calls through three pairs of glass fibre strands, each the thickness of a human hair.

P.T.A.T. cost $400 million to lay. The cable is worth around $100,000 a kilometre. But Cable & Wireless believe the service it provides is worth every penny and gives value for money for customers.

And the Mercury must be on standby to service that cable, although there are temporary back up systems to prevent any major problems with phone calls out of the country.

The ship has been called to breaks in the cable twice over the past four years. There was also a break earlier this year nearer to the English end of the cable.

Capt. Porter took over operations of the cableship from Capt. Ian Bosworth, two weeks ago. Previously he spent four years on a similar ship Pacific Guardian which is based in Fiji and maintains Cable and Wireless's cable linking Asia, Australia and the United States. His hometown is Wigan, England, and he has worked for Cable and Wireless since 1967.

He said: "We are like the fire brigade. A lot of people ask why we need a ship that hardly ever leaves port but if there is an emergency we are required to be ready to act.'' Mercury has a crew of 52 Filipinos and 18 British officers ready to sail at 24 hours notice.

If a problem occurred at its furthest point from Bermuda, halfway to England, then Capt. Porter estimates it would take 8-10 days to fix. Over that period Cable & Wireless would go to satellite and the CARAC cable linking Bermuda with the Caribbean.

These problems happen at depths up to two and a half miles which means Mercury has many miles of rope attached to lifting gear capable of hauling 40 tons, much more than would be necessary. Obviously the rope is much heavier than the cable itself.

On board the crew are constantly trained in techniques of repairing the cable, which in normal circumstances should last indefinitely.

Damage is not caused too often in the deeper water and recently the cable has been buried to avoid damage by trawlers, which were a problem, particularly off the United States. Unlike many Merchant Navy ships the cableship is highly manoeuvrable and can be controlled manually using a special joystick and side thrusters. Capt. Porter said: "We often need to hover over an area while we are working there, this is why we have this manoeuvrability.'' The ship also has the capability to stay at sea for three months although it is always on standby for three weeks, which is ample time for an average break.

This week Mercury has been in Hamilton Harbour and returns to Dockyard to its usual berth on Monday.

CABLE READY -- Capt. Bert Porter inspects some of the deep-sea cables his crew are asked to service.

IN TOWN -- The cable ship Mercury rests alongside Number Five Shed this week following a week-long ocean exercise. The ship normally berths at Dockyard.