VICTORIA -- The Royal Canadian Navy says a sailor missing off the coast of California went overboard in four- to five-metre seas Monday morning.

Master Sailor Duane Earle was last seen aboard HMCS Winnipeg around 5 a.m. local time, according to Commodore Angus Topshee, commander of the Canadian Pacific fleet.

Earle failed to attend a meeting scheduled for 12:30 p.m., leading shipmates to believe he accidentally went overboard, Topshee said Tuesday from Canadian Forces Base Esquimalt.

"The chain of command immediately conducted a muster of the ship's company and two rapid searches of the ship," Topshee said.

The search for the missing sailor is ongoing and is being orchestrated by the Joint Rescue Coordination Centre in California.

HMCS Winnipeg was approximately 500 nautical miles off San Francisco at the time of Earle’s disappearance. The air temperature was 17 C and the seas were approximately four to five metres high, Topshee said.

The ship was returning to CFB Esquimalt after a deployment to the Asia-Pacific region.

The frigate turned back, travelling 80 nautical miles along its route, once it was determined Earle was missing.

The Winnipeg's embarked CH-148 Cyclone helicopter assisted in the search and a CP-140 Aurora patrol plane from Comox, B.C. that was already in the area was reassigned to the search.

The plane remained in the area for approximately 30 minutes before returning to Comox to refuel and rejoin the search Tuesday morning.

"Four- to five-metre waves make it extremely difficult to see a sailor even when he is extremely close to the ship," Topshee said. "We have found his weather jacket, which is his warm, sort of buoyant jacket, on board the ship so he was not wearing it at the time."

Prime Minister Justin Trudeau and Defence Minister Harjit Sajjan said their thoughts are with Earle’s family Tuesday.

“To master sailor Earle's family and loved ones, we are keeping you in our thoughts during this incredibly difficult time,” Trudeau said during a news conference.

“And to everyone aboard HMCS Winnipeg, we are standing with you. I know this has already been a very challenging year for those serving in the Canadian Armed Forces.”

Sajjan said in a tweet that “the entire defence team will be there for his family during this challenging time.”

“We are dedicating all available resources to search for Master Sailor Duane Earle, who went overboard, in hopes of bringing him home,” Sajjan said.

Earle is a 47-year-old boatswain, responsible for a ship's rigging and equipment, and joined the naval reserve in June 1990 in Winnipeg.

“Master sailor Earle is a sailor's sailor with almost 2,000 days at sea,” Topshee said.

The Canadian government says it will use all available resources to find the sailor.

The Royal Canadian Air Force, United States Air Force and California Air National Guard are assisting in the search.