US military units in the Pacific have launched a major search operation after a ship's master was reported missing from a bulker off the island of Guam.

The 47-year-old mariner is said to have fallen overboard from the Panamanian-flagged 82,151-dwt Rising Wind (built 2014).

A US Coast Guard (USCG) C-130 aircraft, a US Air Force C-130 and the USCG cutter Sequoia were immediately deployed to join the search with the reporting vessel.

Joint Rescue Sub-Center (JRSC) Guam is also said to be assessing the availability of any Automated Mutual Assistance Vessel Rescue System (AMVER) ships in the region to assist.

Four additional commercial vessels are said to have volunteered to assist with the search, a USCG spokesman told The Guam Daily Post.

“In cases such as this one, we often rely on our partners in the region to coordinate effective searches and cover vast areas,” said a JRSC Guam spokesperson.

“The Air Force is augmenting our air asset with another aircraft to cover more search area faster than we can do alone.”

Late on Tuesday JRSC Guam is said to have received a report from Rescue Coordination Center Australia stating that they received a call from the first mate of the bulk carrier reporting the vessel’s master was missing.

“The master was last seen in his cabin, feeling ill, wearing a dark-blue winter jacket, brown pants, and slippers,” the USCG said.

“Upon realizing the master was missing, the Rising Wind’s crew turned the vessel around and began retracing their course.”

Databases show the vessel is operated by Japan's NS United Marine. A company spokesperson was unable for comment when contacted by TradeWinds.