Four Dutch men plotted to smuggle more than £16 million of cocaine into the UK by using a "James Bond"-style underwater vehicle, a court has heard.

Henri Van Doesburg, 68, Arnold Van Milt, 49, Roderick Van Doesburg, 23, and Darryl-Jay Van Doesburg, 22, plotted to remove 108kg of the drug from a ship in Scotland using a Seabob vessel and other scuba diving equipment, Leeds Crown Court heard.

The men went on trial today charged with conspiracy to import illegal drugs into the UK.

Paul Mitchell, prosecuting, told the jury the men were arrested after customs officers found more than 50 packages of extremely high purity cocaine in the rudder space of the Cape Maria vessel at Hunterston, near Largs, Ayrshire, on May 9.

He said the "enormous" amount of the drug had a potential street value of around £16.2 million.

Mr Mitchell said Van Milt, Roderick Van Doesburg and Darryl-Jay Van Doesburg were arrested in Seamill the same evening. Henri Van Doesburg was arrested in Aalsmeer, in the Netherlands, the next day.

The prosecutor said Van Milt, Roderick Van Doesburg and Darryl-Jay Van Doesburg all had scuba diving experience and planned to access the drugs in the ship from the outside.

When police searched their car and an inflatable speedboat, they found dry suits, other scuba diving equipment and the Seabob.

Describing the underwater vehicle to the jury of nine women and three men, Mr Mitchell said: "You might have seen them used by James Bond and James Bond's adversaries."

He added: "It's the kind of thing you use if you need to travel underwater at high speed."

Mr Mitchell said that a week and a half before the drugs were seized, Van Milt and Henri Van Doesburg travelled to Cleethorpes, North East Lincolnshire, where they were later joined by Henri Van Doesburg's son Roderick Van Doesburg and grandson Darryl-Jay Van Doesburg.

While they were there, they were seen by a number of people launching a rigid inflatable boat - known as a RIB - from unusual places and leaving the boat on sand banks. On one occasion, lifeboat officers and coastguards noticed the boat floating unattended off the coast of Cleethorpes.

Mr Mitchell said: "The men were attracting significant attention in the town."

The prosecutor said a ship named the Indian Friendship was moored nearby at the same time. This ship had previously had 148kg (326lb) of cocaine seized from it while it was in Rotterdam.

Mr Mitchell said: "There is a clear similarity between what the Indian Friendship was up to and what the Cape Maria was up to. They were both bringing large amounts of cocaine into this continent."

The jury heard that the defendants left Cleethorpes the day after the Indian Friendship left the area. Henri Van Doesburg returned to the Netherlands while the remaining three men travelled to Scotland.

Mr Mitchell said the men booked into a hotel near the mooring place of the Cape Maria and visited a diving school in Largs to inquire about hiring equipment.

A customs officer staying in the same hotel noticed the three defendants and the RIB outside the hotel.

On May 9, customs officers searched the Cape Maria and seized the cocaine.

The three defendants were stopped by the police by chance while they were in their car that day but they were arrested later that evening and brought back to England where they were interviewed by National Crime Agency officers.

Mr Mitchell said: "The motivation to become involved in this crime is a straightforward one.

"The potential profits you can make are absolutely extraordinary.

"This is not a small amount of cocaine for anyone's personal use. It goes without saying this is an enormous amount of cocaine."

Searches carried out after the arrests revealed evidence about the men's diving experience, Van Milt's links to Columbia - where he had travelled on a number of occasions - and links between the defendants and the ships.

Mr Mitchell said Henri Van Doesburg booked three hotels rooms in Rotterdam in March at the same time as the Cape Maria was in the port. The party checked out of the hotel when the Cape Maria left.

Henri Van Doesburg, Roderick Van Doesburg, Darryl-Jay Van Doesburg and possibly Van Milt then booked in to a campsite in North Lincolnshire, where the Cape Maria had travelled from Rotterdam.

In April, Henri Van Doesburg booked another hotel room in Rotterdam when the Indian Friendship was at the port.

Computer searches had been made about the ships and a document about the Cape Maria was discovered on one of Van Milt's phones.

Mr Mitchell said: "There are clear connections between the defendants and the Cape Maria.

"The Cape Maria importation of cocaine in May was merely an example of an ongoing conspiracy of repeated importations of large quantities of cocaine into Europe on vessels from South America."

The defendants deny the charge.

The trial continues.