The delicate operation to relocate the wreck of a First World War German submarine has begun in the Dover Strait, the world’s busiest shipping lane.

The UB38 has laid on the seabed for 90 years but in recent years has been identified as a potential risk to shipping, now that increasingly deeper draught vessels are navigating the south-west bound lane.

The wreck lies at a swept depth of 23.5 metres. The minimum clearance depth required is 26.5m to align it with the surrounding depth.

Trinity House, the general lighthouse authority for England and Wales with responsibility to ensure the safe navigation of this stretch of water, has appointed a consortium to relocate the wreck.

Jeremy de Halpert, executive chairman of Trinity House, said: "Over recent years there has been a noticeable increase in the number of deep draught vessels using the Dover Strait.

"We have a statutory duty to ensure that waterways within our remit remain safely navigable.

"In order to ensure this we have consulted with all concerned parties and have concluded that the best course of action available to us is the relocation of the wreck.

"It is essential that the clearance depth in this section of the Dover Strait is increased and this can only be achieved by lifting the wreck from the seabed and repositioning it in the vicinity which is clear of the deep draught vessel’s route.

"A seabed survey has revealed that it would not be possible to resettle the wreck where it currently lies, and the other option of marking the site with floating aids to navigation would only create greater restriction."

Dover Coastguard will be making regular broadcasts to vessels in the area.

A 500m radius safety zone will be in operation.