Sue Farley takes the plunge into the cold, watery underworlds of the upper South Island.
Eleven degrees is cold in anyone's books, so if you're used to diving in the warmer waters of South-east Asia, Australia or even Northland, you'll notice the difference in the cool waters of the South Island.
The dives at the top of the island are stretched across an area 150km long and 100km wide. Nelson is the only city; Blenheim, Picton and Kaikoura are the main towns. Around lie mountains, rivers, sea and the Marlborough Sounds.
The dives vary immensely, covering a range of experiences and difficulties. All are available through commercial operators, and most are recommended as guided dives.
Riwaka River source
Just an hour's drive out of Nelson is a challenging freshwater dive at the resurgence of the Riwaka River. In ice-cold waters that rise up from deep under the marble mountains of the Kahurangi National Park, this dive enters a huge cave system. A highlight is the cathedral, an 80m-long cavern that rises 50m in height and is 50m wide.
A guide is essential, as several of the caves are dead-end, and visibility and orientation can be difficult. Several rivers rise from under the mountains, with cold, clear water that may have been under the ground for 100 years. Waterways spring to the surface through labyrinthine channels and caves that can leave divers disoriented.
A dry suit is a good idea, along with at least two torches, a light stick, 100m of line and lots of air. After a 15m-long tunnel, a deep pool, some small rapids, and another 60m sump, it can be a long dive through to the cathedral. It is essential to use a line here, as the visibility can drop to virtually nil.
Once there, however, the drama has been worth it, with an Aladdin's cave of limestone formations, stalagmites and stalactites awaiting.
Mikhail Lermontov
The South Island's most famous, and recent, wreck dive lies on the edge of the Marlborough Sounds, in Port Gore. Easily accessed by boat from Picton, this dive explores the 200m-long Russian cruise liner that hit rocks and sank in the 1980s.
Heading from Picton, it's a great day out. The first three hours are spent cruising out through Queen Charlotte Sound to Cape Jackson, on the edge of Cook Strait. From there, it's only another 40 minutes to the site.
The wreck lies on its side in 30m of water. The top side is easily accessible at around 12m although, with the strong seasonal currents, visibility can be a problem. A guide is strongly recommended.
The overwhelming impression is of the ship's sheer size. The scale is immense, with the giant propeller and the funnel, complete with Russian hammer and sickle still emblazoned on the side. The bridge is easily located and one of the few places on the wreck where it is easy to get a peep inside.
Divers are discouraged from entering the wreck without a guide, as the maze of corners, corridors and rooms can be disorienting. The second dive of the day gives a chance to move further over the giant hull. Familiarity gives the confidence to check out the swimming pool and the anchor up on the bow, and to cruise around the fittings on the now vertical deck.
D'Urville Island
On the outer western edge of the Marlborough Sounds is D'Urville Island. The island is large, sparsely inhabited, hauntingly beautiful and covered in forest and isolated farms.
The coastline is littered with hidden bays and rocky outcrops. Several of the smaller islands off-shore - the Trios, Rangitoto and Stephens Islands - hold some underwater surprises. Tidal currents bring a rich food supply to the area, and marine life is prolific - dolphins, whales, many species of fish, sponges, seaweeds, anemones and bryozoa.
Although it's a dangerous spot and definitely not for beginners, there is good diving at French Pass. This narrow channel runs between D'Urville Island and the mainland, and creates awesome flows when the tide is running. This spot is also well known for its bird life, including petrels, shearwaters, many kinds of gull and five different kinds of shags.
Kaikoura Coast
The Kaikoura coastline is only a couple of hours' drive south from the Sounds and offers stunning reef dives and close encounters with playful little fur seals.
Also fed by warmer ocean currents, the marine life along the rough and rocky Kaikoura Coast is world famous. Whale-watching is well known here but is not the only attraction. Dolphins and seals are seen daily and are a highlight of the diving.
Huge kelp forests and weed and sponge beds add to the flavour, and Kaikoura's namesake, the koura or native lobster, can also be seen. Photography is good, with reasonable visibility and depth. Shore diving is also a possibility from Paiha Point.
Waikoropupu Springs
This one is really worth the cold. Like the Riwaka River, Pupu Springs (as they are commonly known) also rise from deep in the marble mountains of the Kahurangi National Park and bubble to the surface under enormous pressure, this time on the other side of the Takaka Hill.
Only a two-hour scenic drive from Nelson, the springs are renowned for their extremely clear visibility and range of plant and moss life.
Sands and gravel dance above the vents and native freshwater crays, trout and salmon cruise the springs. Colours are strong in the clear, shallow water, almost giving the impression of diving into a giant, round, goldfish bowl.
But for some, the highlight of the dive is the ride down the Waitapu River afterwards. Take off your weight belt and tank and slide into the fast-flowing water as it leaves the springs and heads down towards the sea. The water is shallow, but the boulders are smooth. Young native bush and draping ferns overhang the river, and salmon and trout flash by in this crazy blast down the river.
In line with requests from conservation groups and local iwi, changes in by-laws have limited dive options at the springs. Check the situation with local Department of Conservation offices or a dive shop in Nelson or Motueka before diving.
Other options
There are many more dives around the top of the South Island. Most are suitable only for certified divers.
NZ Sea Adventures at Kaikoura offers introductory dives with seals for uncertified divers, and several operators run learn-to-dive courses.
The most comfortable time for diving in these cooler waters is from September to April. Summer makes a big difference to the ambient temperature above and below the water.
The Marlborough Sounds, in particular, has countless spots where great diving is to be had just jumping off the boat during an overnight mooring. The water is cool but usually clear.
A number of islands in the outer sounds are wildlife sanctuaries, some with limited access, but all offer a variety of reefs, marine life, birds and sea vegetation. Talk to the local dive companies about the best options at these lesser-known places.
Also in the region is the Abel Tasman coastline, on the western side of Tasman Bay, near Nelson. Once again, the scenery is delightful, the whole area is a well-trod national park. Seals and little blue penguins feature at Tonga Island and there is a range of fish life and some interesting algae and shellfish.
CASE NOTES
Required gear
Unlike further north, a 7mm wetsuit is basic equipment here, with a good hood, thick boots and heavy-duty gloves.
The water around the South Island is generally influenced by sub-polar currents heading north from the Antarctic regions. Only around D'Urville Island and Kaikoura are the currents exposed to warmer waters, and then are only marginally warmer. For cave-diving a dry suit is recommended.
Contact
Pupu Springs, Riwaka River source, D'Urville Island and French Pass - Big Blue Nelson, ph (03) 546 7411
Marlborough Sounds, Mikhail Lermontov - Divers' World Picton, ph (03) 573 7323
French Pass, D'Urville Island, outer Marlborough Sounds - French Pass Sea Safaris - ph (03) 576 5204
Kaikoura Coast - NZ Sea Adventures, Kaikoura, ph (03) 319 6622
