Hull number begin by 1 (reserved for aircraft carriers): great statesmen (Presidents, Vice Presidents, etc.) Hull number begin by 2 (cruisers and destroyers): Indonesia's main islands (for cruisers) and National heroes (for destroyers) Hull number begin by 3 (frigates, ocean escorts, corvettes): national heroes Hull number begin by 4 (submarines, submarine tenders): mythical weapons (for submarines), National heroes (for submarine tenders) Hull number begin by 5 (amphibious ships, LSTs, LPDs, LCUs, command ships): main and strategic bays (for LSTs), big cities (for LPDs), small cities (for LCUs), National heroes (for command ships) Hull number begin by 6 (fast attack ships): mythical weapons (previous names for missile boats), traditional weapons (current names for fast missile boats), wild animals (for fast torpedo boats) Hull number begin by 7 (minesweepers, minehunters, mine countermeasures ships): every island begin with letter "R" Hull number begin by 8 (patrol boats): native fishes and sea creatures, native snakes and wild reptiles, wild insects, geographical places (such as towns, lakes or rivers begin with "si-", like Sikuda, Sigurot, Sibarau) Hull number begin by 9 (supporting ships, oilers, tugs, troops transports, oceanographic research ships, sailing ships, etc.): volcanoes, cities, mythical figures, geographical capes and straits