The toilet bowl.
Gili Tepekong is a rocky island east of Candidasa with vertical walls dropping past 30 metres on every side. There's an underwater cave at 18–26 m on the south side, draped in soft coral and packed with sweepers and lobster. The cave is the headline.
The legend is the current. Tepekong sits at a current convergence point, and at certain tide states a downcurrent vortex forms on the north side — locals call it 'the toilet bowl'. Done right, you avoid it and ride a big drift around the island. Done wrong, you get pulled to 40 m and have to fight your way out. Guides who dive Tepekong daily know exactly when to go.
"When Tepekong's good, it's the best dive on Bali."
★★★ — for divers with strong-current and deep training. 50+ logged dives, AOWD minimum, ideally with a Bali-experienced guide. The cave is the consolation prize when conditions don't allow the full island circuit.