More U.S. and Mexican assets have joined the search for a crew member reported missing from the Coast Guard cutter Waesche Tuesday morning, Coast Guard officials said Thursday evening.

The unidentified crew member was discovered unaccounted for while underway approximately 300 nautical miles south of Mexico, according to a Coast Guard statement. The missing crew member had been last seen eight hours earlier before.

“The cutter immediately deviated from its routine counter-drug patrol tasking and initiated a comprehensive search effort,” according to the Coast Guard. The cutter crew launched its helicopter and unmanned aerial drone.

More aircraft joined the search area: Two Customs and Border Protection Dash-8 aircraft from Joint Interagency Task Force – South; a C-130 aircraft from U.S. Air Force 39th Rescue Squadron; a C-130 aircraft from Coast Guard Air Station Kodiak in Alaska; and an offshore patrol vessel and maritime patrol aircraft from the Mexican Navy.

“The search area and effort are vast, and the operation is being carefully coordinated to ensure maximum coverage and effectiveness,” according to the Coast Guard.  “The circumstances around the search and rescue case are under investigation. “

The 418’x54’ Waesche, commissioned in 2010, is the second Legend-class national security cutter, carrying a crew up to 170, and is homeported in Alameda, Calif.