THE US Coast Guard is preparing for demonstrations to protest oil drilling in the Chukchi Sea this summer following protests at New Zealand's Shell Oil drilling ship, said Alaska USCG chief of staff Captain Norman (Buddy) Custard.

To prevent any disruption caused by the protests likely to take place during its busiest fishing month of June, the coast guard it will deploy a small boat force from Dutch Harbor, said Capt Custard.

The presence of the USCG is to make sure port activity isn't disrupted for vessels and for food, fuel and other shipments into the city of Unalaska.

"We're not here for Shell, we're here to ensure safe commerce and transportation," he said, reported the local paper, Juneau Empire.

It also is on alert for increased air traffic between Shell's Barrow staging area, other possible shipping incidents and offshore operations which may require a coast guard response.