Seafarers have been warned about a section of dry dock and a damaged sea plane adrift near the island.

The sea plane was being used by a US university for research when it was abandoned 250 miles west-southwest of Bermuda after an emergency landing.

The US Coast Guard said: “The seaplane left Elizabeth City, North Carolina, early on Saturday morning and was forced to make the emergency landing after striking an object during take-off, which damaged the aircraft’s front node.”

The five people on board were picked up by merchant ship Polar PeruUSS Mason.

A notice to mariners was later released by the US Coast Guard to warn boats about the plane.

The Coast Guard has also alerted mariners to a large section of dry dock spotted last week about 280 miles south of the island.

A spokeswoman said: “There are no plans to salvage the floating dock at this time, due to distance.

“If the floating dock threatens Bermuda territorial waters, the department will take the appropriate action.”

The spokeswoman admitted Bermuda did not have the ability to recover the dock.

She said the US Coast Guard would be in a better position to deal with the problem because of the size of its fleet.

She added: “The United States Coast Guard are aware of the latest sighting and have issued notice to mariners. Any further sightings are forwarded to USCG Miami and Bermuda Radio.

“We cannot confirm whether other pieces of barges are out there.”

The US Coast Guard said the navigational hazard is a section of dry dock from the former Avondale Shipyard in Louisiana.

The dock was being transported to the Canary Islands last year but broke apart during the journey.

The dry dock section is estimated to be about five metres wide, four metres high and ten metres long.

The Department of Marine and Ports spokeswoman said the dock was considered a significant danger to mariners because it was unlit and low in the water.

She said: “Floating obstructions on the high seas are not unusual considering the number of marine traffic worldwide.

“Coast stations rely on passing marine traffic to report these obstructions that are beyond coastal radar capabilities.”