On 16 January 1942, "Ro-65" got underway in company with "Ro-67" to support the Japanese invasion of Rabaul on New Britain in the Admiralty Islands, ordered to patrol south of Cape St. George on New Ireland. On 21 January 1942, the two submarines received orders to join the submarines of Submarine Division 33 — , , and — in patrolling in St. George's Channel while Japanese forces landed at Rabaul, but they found no targets. "Ro-65" arrived at Truk on 29 January 1942.