Wellington divers are lucky. They live in a beautiful city which is surrounded by the sea.
Within easy car distance they have the choices of diving in the harbour, around the harbour entrance, along the south coast, at Makara or along the coastline at Titahi Bay. Driving a little further includes areas of the north coast at Pukerua Bay, or the eastern and southern coasts of the Wairarapa. Those with boats also have the pleasure of some of the more isolated pieces of southern coastline, plus the waters around Mana and Kapiti Islands.
However, for all this great range of dive sites, Wellington is not hailed as one of the diving Mecca's of the Pacific. Two of the significant differences between diving in Wellington and, say, diving at a Pacific island are the temperature and clarity of the sea water.
In Wellington divers tend to dress well, using 7mm foam neoprene wet suits, or perhaps dry suits, to overcome heat loss problems in our relatively cool water. In Wellington Harbour I recorded a midwinter temperature of 6° C (64 F) (July 95) and in midsummer 19° C (77 F) (January 96), averaging around 14° C (72 F)..
The clarity of Wellington sea water is also something that we have little control over. Diving visibility, or 'The Viz', plays a big part in determining the level of enjoyment gained from a dive. The range of vision can vary from nil (hang on to an octopus hose or lose your buddy), through improving (easy to observe the environment and maintain buddy contact), to jaw-dropping (10 metres or more - What's my buddy doing away over there?) Well, jaw dropping is a relative term I suppose.
Wellington seawater clarity varies due to the effects of coastal currents, tidal streams, silts and pollutants from rivers, streams, storm water drains and sewers, and the effects of wind on the sea when it creates swells (above) and surge (below) the surface.
A rapid guide to dive conditions may be had by observing the sea state. Heavy swells on the surface and large breakers are an indication of strong surges below water level. There will be a lot of silt stirred up and the visibility will be low.
A flat sea may be an indication of good diving to come, but yellow or green water are indications of suspended silt and low visibility. If the water is deep blue, postpone the barbecue for a few hours and go diving! Cleaner water can sometimes be seen out at sea and boat divers commonly have high visibility dives when shore dives are poor.
Steady wind conditions for about three days produces great diving. Northerly winds have the waves beating in on the north coast but tend to flatten swells on the south coast, improving diving there. Likewise, southerly winds churn up the south coast but flatten swells on the north coast. Given steady wind conditions, silt drops out of the sheltered water and visibility rapidly improves. To frustrate divers the wind commonly alternates daily between blowing from the north then from the south. Sigh !!
Rainwater has little direct effect on the sea, but makes itself felt within hours at stormwater outlets, streams and rivers. Dirty water soon obscures vision after the onset of rain.
Wellington Harbour South Coast North Coast