renamed the Maritime Command in December. The name changes reflected the internal restructuring within the Singapore Armed Forces and the growing realization that maritime security was a crucial element to national security. Headquarters was shifted ashore to Pulau Belakang Mati in 1968. In order to develop local expertise in seamanship and naval engineering, 160 naval recruits underwent training by Royal New Zealand Navy instructors in 1969. At the same time, aspiring officers were sent overseas to learn from established navies in Australia, Britain, Canada and New Zealand. The Maritime Command launched an expansion program with the objectives of combating sea robberies and smuggling, and improving seaward power projection. In June 1968, six Independence-class patrol crafts were purchased and commissioned between 1970 and 1972, marking the first purpose-built ships the Navy possessed. Part of the urgency stemmed from British prime minister Harold Wilson's intention to withdraw British troops East of Suez by 1971, which would leave a security vacuum, though a smaller British presence eventually remained under the Five Power Defence Arrangements. Growing constraints and strategic need for a base located nearer to the strait was solved by the opening of Brani Naval Base in December 1974. The foresight was validated a few weeks later when terrorists from the Japanese Red Army attacked an oil complex on Pulau Bukom and hijacked the Laju ferry. Four vessels, RSS Sea Hawk, RSS Independence, RSS Sovereignty and RSS Daring together with the Marine Police, were able to surround the fleeing ferry and prevent it from escaping. Colonel James Aeria would be the final commander of the Maritime Command. On 1 April 1975, the Maritime Command was renamed the Republic of Singapore Navy as part of the reorganisation of the Singapore Armed Forces into three distinct services, and has kept the name ever since. Fleet modernisation The RSN was the first navy in the region to successfully fire a live anti-ship missile when RSS Sea Wolf fired two Gabriel missiles in March 1974. From 1975 to 1976, six Sea Wolf-class missile gunboats were commissioned, which proved vital during Operation Thunderstorm when they were deployed to patrol and apprehend the influx of boat people fleeing the fall of South Vietnam. In order to support sealift operations, six County-class tank landing ships were purchased from the United States; these were popularly referred to as dollars ships due to the price ($1) paid for each vessel. Two Bluebird-class