An icebreaker carrying a key piece of equipment for Arctic drilling planned by Royal Dutch Shell off the northern coast of Alaska was forced to return to dock after a hole more than three feet long was discovered in its hull, the company said Tuesday.

It was unclear if the mishap would delay Shell’s plan for drilling this summer.

The crew of the Fennica discovered the leak in a ballast tank on Friday as the ship was leaving the channel in Dutch Harbor, Alaska, on its way to the Arctic, Shell spokesman Curtis Smith said.

The company had not determined if repairs can be made to the breach measuring about 39 inches long and a half-inch wide while the ship remains in Dutch Harbor or if it will have to go to drydock for the work.

Smith said bad weather had kept Shell from getting an inspector to Dutch Harbor for almost two days.

Shell had hoped to begin drilling the third week of July and is still awaiting a final drilling permit from the government.

The Fennica, one of many support ships for two drilling rigs, was transporting a capping stack that would be used to seal a well in case of a blowout.

Smith said other options were being considered if the Fennica cannot continue the trip, including transferring the equipment to another ship in the fleet.

It wasn’t immediately clear if that would require new permits from the government, another possible setback.

Jessica Kershaw, a spokeswoman for the U.S. Department of the Interior, said Shell’s proposal for drilling activity in the Chukchi Sea this summer remained under review.

“As we’ve said from day one, Shell will be held to highest safety and environmental standards,” Kershaw said in a statement. “This includes having on hand the required emergency response systems necessary for each phase of its drilling program.”

Shell did not immediately know how the Fennica was damaged. Smith said the inspectors planned to re-enact the ship’s movements through the channel to see if there is a shallow hazard that wasn’t previously charted.