Indonesia has many of the world's best diving sites , one of the finest of which is Pulau Bunaken off Sulawesi , where the vast diversity of tropical fish and coral is complemented by visibility that can reach over 30m. Bali has many good sites including the famous Liberty wreck, and reputable tour operators at all major beach resorts; Lombok 's operators are limited to Senggigi and the Gili Islands; and in Kalimantan there's fine diving off Pulau Derawan. The best time for diving is between April and October. Most major beach resorts have dive centres, but once you get further afield you'll probably have to rely on live-aboard cruises or even on having your own gear. A day's diving with two tanks, lunch and basic equipment costs anything from $30 to $100. Be sure to enquire about the reputation of the dive operators before signing up, check their PADI or equivalent accreditation and, if possible, get first-hand recommendations from other divers. Be aware that it is down to you to check your equipment , and that the purity of an air tank can be suspect, and could cause serious injury. Also check your guide's credentials carefully, and bear in mind that you may be a long way from a decompression chamber.