Police have opened a missing-person investigation, while firefighters and the Coast Guard are combing North Shore beaches for a 51-year-old mainland tourist who hasn’t been seen since Wednesday, when he told a friend that he was going surfing for the first time.

The Coast Guard, using its 87-foot Coast Guard cutter Ahi and a MH-65 Dophin helicopter, covered 159 square miles in its search Wedmesday night. It planned to expand today’s search to an area west of Sunset Beach.

The Coast Guard is concentrating its efforts from four miles off shore, while the fire department is working close to shore and on North Shore beaches. Fire department personal watercraft are also being used.

Capt. Terry Seelig, Honolulu Fire Department spokesman, said fire rescue personnel were called at 9:45 last night when the Coast Guard sought the department’s assistance. The Coast Guard said the surfer was reported missing at 9:30 last night.

Seelig said authorities aren’t sure if the man went surfing near Sunset Beach, where he had been staying with a friend. Seelig said there wasn’t much surf at Sunset Beach on Wednesday.

The visitor was supposed to fly to Colorado on Wednesday, his roommate told authorities. She told authorities that the man had never surfed before, but was an expert swimmer.

However, Seelig said the woman did not report the man missing until late in the day, when she returned to find his rental car still parked at her house along with his wallet, keys and clothing.

Seelig said a white surfboard, which the woman said the visitor could have used to surf, was found by another person at Rocky Point near Haleiwa south of Sunset Beach.

Surf on the North Shore was in the 2- to 3-foot range Wednesday.

Firefighters searched the beaches from Kawela Bay to Rocky Point and flew over the area with the department’s helicopter Wednesday night.

This morning the fire department resumed its helicopter search and firefighters are searching the beaches on the ground.