A shortage of frigates ready to go to sea is forcing the Royal Canadian Navy to fly hundreds of sailors back and forth from the Middle East.

HMCS Toronto is based in the Arabian Sea, but rather than sail the vessel back to port the navy will instead fly a new crew across the Atlantic and bring the old crew back by the same means.

The unconventional switch is happening as the navy modernizes 12 of its frigates. The navy said it doesn’t want to abandon its commitments patrolling the Middle East.

“This is the most effective and expeditious way to keep our operations going in the Arabian Sea,” said Lt.-Cmdr. Bruno Tremblay, a spokesman for the navy in Halifax.

Five hundred sailors, two helicopters and several dozen civilian dockworkers will begin the crew swap in the upcoming weeks.

The navy said a Canadian Forces aircraft will be used.

HMCS Toronto sailed from Halifax in January.