Fiordland

Nothing is dived from shore. At Milford the boats leave the wharf and are on site within minutes, and the walls block the ocean swell well enough that diving can go ahead in weather that would stop a charter on the open coast; the limiting factor is often the mountain road in, which closes for snow and avalanche risk. Doubtful and the fiords south of it are worked as overnight or multi-day charters, with divers living aboard and the running order set by the weather.

The rock walls carry straight on below the waterline, so you drop in against a vertical face and follow it down. The top few metres are the freshwater layer: dark, tea-coloured and blurred where it meets the salt water, and it takes a moment for the view to settle once you are through it. Below it the water is clearer but dim, and torches stay on from the start. Silt and boulder slopes collect at the foot of the walls, and heavy rain pushes the surface layer deeper and darker.

The black coral is the reason to come, and it is not black: living colonies are white, standing off the rock in fans and bushes, with red snake stars wound tight around the branches. Around them the walls carry sea pens, anemones, brachiopods and nudibranchs. It is quiet diving, the interest lying in working slowly along a few metres of wall rather than watching open water, and the colonies are slow-growing and easily broken, so buoyancy counts for more here than depth experience.

Cold, dark and remote, it suits divers who already own a drysuit and use it regularly; hood and gloves are not optional at 8-16C. It is a poor pick for a first cold-water trip, or for anyone who needs the week to go to plan, since rain falls in every month, sandflies are relentless ashore and charters lose days to weather. Divers who like terrain and unusual invertebrates get something they will not easily find elsewhere.