consist of the combat trainer as well as diving and steering trainer among others. It will additionally feature a virtual procedural trainer that replicates the submarine with all its more than 12 million parts, that offers both physical and tactile training opportunities for the crew members while ashore. Enlistees to the Naval Diving Unit are selected based on their eyesight and medical fitness and trained at Frogman School located within Sembawang Camp. Trainees are required to pass a vocational assessment prior to beginning nine weeks of basic military training. Those who qualify then undergo the twenty weeks Combat Diver Course where they are taught dive theory and must qualify for drown proofing, pool competency and survival skills requirements. Current fleet Frigates The multi-role stealth frigates entered service with the RSN in 2007 and are derivatives of the French Navy's . The frigates are key information nodes and fighting units, and were, at time of launch, "by far the most advanced surface combatants in Southeast Asia" with a special surface-to-air missile configuration which combines the Thales Herakles radar with the Sylver A50 launcher and a mix of MBDA Aster 15 and 30 missiles. Other armaments include Boeing Harpoon missiles and an OTO Melara 76 mm gun for surface defence. Equipped with Sikorsky S-70B naval helicopters, an international derivative of the Sikorsky SH-60B Seahawk. These naval helicopters feature anti-surface and anti-submarine combat systems, extending the ship's own surveillance and over-the-horizon targeting and anti-submarine warfare capabilities. The naval helicopters are part of the 123 squadron of the RSAF and piloted by air force pilots. Two more S-70B helicopters were ordered in February 2013. The lead ship of the class, RSS Formidable was built overseas in Lorient, France and commissioned locally on 5 May 2007, marking the 40th anniversary of the RSN. The final two ships, RSS Stalwart and RSS Supreme were commissioned on 16 January 2009. The six frigates form the First Flotilla of the RSN. Littoral mission vessels The Independence-class littoral mission vessel is a class of eight surface platforms succeeding the Fearless class. In January 2013, the Ministry of Defence awarded ST Engineering a contract to build and design eight vessels. A subsidiary of the company, ST Marine was charged with building the ships at Benoi Yard and integrating the combat systems supplied by the group's electronics arm, ST Electronics. The class was designed with the "lean manning" concept to facilitate