Pearse Resurgence

A very cold, very deep resurgence (a spring where an underground river returns to the surface) in New Zealand's Tasman region, explored by expedition divers to 245 m. One of the deepest cave dives made anywhere.

The Pearse Resurgence is a resurgence of the Pearse River on the Mount Arthur range in the Tasman region of the South Island. Since 2007 expedition divers have pushed it progressively deeper, exploring two separate deep branches, one to 229 m and one to 245 m, and the cave continues beyond both.

The water is about 6 °C, which makes these dives exceptionally demanding. The expedition leader describes cold, fatigue and untested decompression at these depths as the main hazards, and says most of the team's equipment is heavily modified or home-made, with scooters and lights the limiting items. The site is an exploration project rather than a recreational dive, and no public access arrangements for divers were found.

The resurgence is generally described as the lower outflow of the Nettlebed cave system, which cavers connected to the Stormy Pot entrance on Mount Arthur in 2014 to form the deepest known cave in the Southern Hemisphere.

A resurgence of the Pearse River from a karst cave system; the expedition leader gives a water temperature of 6 °C.

The expedition leader describes the Pearse as the eighth-deepest cave dive ever made. It has been the focus of the Wet Mules team's deep-diving expeditions since 2007, including a 2011 biosurvey.

One diveable entrance, the resurgence pool. The upper Nettlebed and Stormy Pot entrances are dry caving entrances.