Crystal Bay

The site

Crystal Bay is two dives in one. Inside the bay it is a benign, bright sand-and-coral slope. Out at the point where the channel runs, it is one of the most demanding sites in Bali, and the two are separated by a short swim.

The draw from July to October is the oceanic sunfish, the mola mola, which rises out of deep cold water to be cleaned. That same upwelling is what makes the site cold and what drives the currents.

What you will see

• Mola mola (July to October)
• Bannerfish
• Napoleon wrasse
• Reef sharks
• Nudibranchs on the inner slope

Diving it well

• Dive it with a guide who works the site regularly. The safe profile depends on the tide state on the day, and there is no version of this dive where reading the water yourself from the boat is enough.
• If you feel yourself being pushed down, swim horizontally out of the flow toward the reef — not up against it. Fighting a downcurrent vertically is how divers exhaust their gas.
• Bring more exposure protection than Bali suggests. Thermoclines below 20 m routinely drop into the low twenties and colder.