Vice Admiral Barry Costello, Commander, U.S. THIRD FLEET discusses the importance of coalition interoperability with commanding officersâ from the Republic of Korea (ROK) Navy. Vice Admiral Costello toured ROK ships in port Pearl Harbor, HI during the in port phase of the Rim of the Pacific (RIMPAC) 2006 exercise. U.S. Navy Photo by PH2(AW) Grant P. Ammon.