A sailing vessel operated by Youth With A Mission (YWAM), the Hawai'i Aloha, has capsized four miles from the Kona coast of the Big Island of Hawai'i. A crew member is missing and the captain has been hospitalised with injuries which are not life-threatening.

The boat is one of a fleet used by the Christian charity for mission and ministry in hard-to-reach places in the Pacific region and bring medical and dental care, clean water systems and educational initiatives.

According to YWAM, the 75-foot yacht headed out to sea after receiving a weather warning in order to ride out dangerous conditions. It was cutting into rough waves approximately four miles from shore when a series of large waves hit the vessel broadside, flipping it twice.

The crew shot off flares and four of the five abandoned ship into an emergency life raft, from which they were rescued by two jet ski operators.

The vessel was loaded with supplies and was due to depart for Christmas Island.

YWAM said in a statement: "This is the first marine tragedy in YWAM's decades of service.

"Our first concern is for the safety and well being of the crew involved in this incident. Out of respect and privacy for these individuals, we ask for your patience and understanding at this time.

"YWAM Ships' Fleet Support is working in cooperation and collaboration with Hawai'i Island's Department of Land and Natural Resources and Hawai'i's Coast Guard. A full search of the vessel is under way and the search for the missing crew member is ongoing."