Boat users are being asked to report anything suspicious

Since 1999, cannabis with an estimated street value of about �2m has been seized by customs officials.

In all cases, the drugs have come from nearby Normandy and the Customs Department says the island's experienced sea-farers could help by reporting suspicious activities.

The department has written an article in 2004's tide time and yachting information booklet, the Jersey Cruising Guide.

It makes people think 'this is actually happening' Steven Le Marquand

The booklet is produced for the St Helier Yacht Club and South Pier Marine, and the article asks boat users to be vigilant and report anything they feel is suspicious.

In some smuggling cases, drugs are believed to have been dropped from yachts or fast rigid inflatable boats along the east coast.

In other cases, attempts have been made to take drugs through ports including St Aubin and St Helier.

Customs officials Steven Le Marquand said the article includes case studies, which he believes brings more reality to the report.

He said: "It refers to real life situations that the department has come across.

"I think it makes people think 'this is actually happening', not something that might happen, or could happen.

"I think it reinforces any message we are trying to get across to the general public."

Immigration officials have said in the past they do not believe many immigrants have used the island as a stepping stone to the UK.

But they have some concerns that the closure of the Sangatte refugee camp near Calais may lead to more people trying to use Jersey as way of reaching Britain.

Again boat owners are being asked to report any suspicious activity.