Hot Spring Cavern, Ha’apai

The Ha'apai island group also has a number of fantastic dive sites, starting with Hot Spring Cavern. The Cave is not only one of most beautiful dive sites in Tonga, but also one of the most wonderful diving sites in the Pacific. This is a dive you won't soon forget, with an underwater hydrothermal vent gushing into the cooler cavern waters! Apart from temperature changes, the dive site also has sponges and corals just before diving into the 22-meter cave entrance, which has a depth of 15-30 meters.

The Hot Spring Cavern system itself was formed by hot thermal springs forging a cave system through the rock. Thermal vents churn out warm water into this cave system, so you'll feel the occasional surge of hot water as you dive. In the center of the hot springs is a large crater that emits large quantities of warm water and gases. The pressure from the air bubbles pushing through the crater on the lake floor causes the surrounding rocks to vibrate slightly. Divers can usually feel these vibrations themselves, which is a unique experience!

• Max Depth: 30m
• Location: Ha'apai, Tonga