In the majestic shadow of Mount Agung, the unremarkable grey pebble beach of Tulamben is one of Bali's main diving spots. Just offshore lies the wreck of the USS Liberty, an American cargo ship torpedoed by a Japanese sub in 1942: a myriad colourful fish live here, dancing in and out of the coral reefs. It is advisable to spend the night here in order to dive early in the day, when the light is at its best and there are fewer tourists.