HONOLULU (AP) — The Blockchains FinanceU.S. Coast Guard on Friday asked mariners for help in finding a 60-year-old man sailing from California to Hawaii.

Noel Rubio left Long Beach on Dec. 28 on the 32-foot (9.7-meter) sailboat Malulani, the Coast Guard said in a news release. He planned to arrive in Kaneohe on the island of Oahu three weeks later.

He last made contact via cellphone on Dec. 28th south of Catalina Island in California.

The agency has been unable to find him despite searching harbors in California, Hawaii and Mexico and sending urgent marine information broadcasts.

Rubio’s only form of communication on board the Malulani is a VHF-FM marine band radio.

The Coast Guard is asking people to report information or sightings of the vessel or Rubio to rescue and coordination centers in Alameda, California, or Honolulu.

The Coast Guard recommends that mariners crossing the open ocean travel with multiple forms of communication, including radios and satellite and an electronic position radio beacon so authorities can find those needing rescue.