Dry (and Stealthy HECS) Winter Diving


Filming in a green and blue winter world. By Sophie Roselt.

By Dave Abbott. Images by Dave Abbott unless otherwise credited.
(Cover image as well as above image by Sophie Roselt.)

Not everyone can afford to head off overseas every winter to those exotic, warm-water locations you see in brochures where everyone dives in board shorts and bikinis, so it is lucky we have some awesome winter diving options right here in New Zealand that can keep your dive habit satisfied over the cooler months … without breaking the bank!

New Zealand winter diving can be super rewarding, especially on those clear calm winter days when you are about to jump into the blue world again after a week of wind and rain! There is often different life about over the winter months too … up in the north we might not see so many of the big fish schools, but we do see more of those species that are less common in summer, like carpet sharks, Spanish lobster, blue moki and fur seals.

A lazy Northern scorpionfish warns me off his patch with a half-hearted gape.

A lazy Northern scorpionfish warns me off his patch with a half-hearted gape.

I’m fairly spoilt having the Poor Knights as my ‘local dive’, with its clear water, diversity of marine life and iconic pelagic summer visitors like manta rays and sunfish, but diving the ‘Knights in winter when the south-facing walls are carpeted with bluebell tunicates and the lower angle of the sun creates shimmering light-rays in the caves and archways is also pretty special.

Another amazing New Zealand winter dive location is Fiordland. The water might be on the cold side, but on those clear, blue-sky winter days there is nothing more spectacular than surfacing from an awesome black coral dive to a 360° panorama of snow-capped peaks … it can make you feel like you’ve just won Lotto!

The only thing that can ruin winter diving is being cold, so it’s pretty obvious that the secret to enjoying winter diving is to stay warm.

A young fur seal spending the winter months in our warmer northern waters.

A young fur seal spending the winter months in our warmer northern waters.

Staying Warm

One word: Drysuit. Divers who haven’t got one will always argue that they are warm enough in their wetsuits, but the truth is that nothing keeps you warm like being dry … it’s a simple formula: Warm + Dry = Enjoyable diving. Nothing beats taking your own little ‘warm air space’ from the world above under water with you, and it’s a pretty special feeling being warm dry and weightless in a liquid environment!

I prefer neoprene drysuits for their greater warmth and comfort factor, and I’ve been diving in the same Oceandry Bravo drysuit for the past 14 years. It is still going strong, but as it has now done about 2000 dives I figured I could justify getting a new drysuit this winter!

For the past two summers I have also been test-diving the new HECS wetsuits with their ‘carbon-grid stealth technology’ and have really liked them, so I thought why not combine a HECS layer into an Oceandry drysuit, and make the first ‘HECS stealth drysuit’ in the world, right here in New Zealand.

When I suggested the idea to HECS and Oceandry (both New Zealand companies incidentally) they were very interested, so we sat down to talk about how it could be done, and the end result was an awesome and very functional drysuit … but one with a difference.

The Stealth Factor

If you haven’t yet heard of HECS, the theory behind the HECS fabric is that it incorporates a carbon grid layer which masks the electrical signals generated by muscle activity – something all living things (including divers) produce. Obviously marine species have other senses too, fish for example can see, smell, hear and feel vibration, but as it is cumulative sensory input that dictates the behaviour and reactions of most species; the less input they receive the less reason there is for them to flee or change their behaviour.

Some winter blue-water at the Poor Knights. Image by Darren Spratt.

Some winter blue-water at the Poor Knights. Image by Darren Spratt.

The aim of my job is to get as close to marine life as possible while trying to film natural, undisturbed behaviour, so it makes sense to take advantage of any new innovations that can help me either be ignored, or regarded as non-threatening rather than being perceived as a potential predator. The HECS technology isn’t a ‘magic invisibility cloak’, but by masking your electrical signature it does eliminate one of the sensory signals that determine how close an animal will let you approach.


Bluebell tunicates on a south-facing wall, something you only see in winter.

Bluebell tunicates on a south-facing wall, something you only see in winter.

Obviously the design of a drysuit and the quality of materials and components used in its construction play an essential role, as they dictate the fit, comfort and durability of a suit. After 18 years diving in Oceandry drysuits I know their suits are well-made, warm, comfortable and tough.

For the prototype Oceandry HECS drysuit I opted for their ‘Impreza’ design which is the most commercial suit in the Oceandry range; made from top quality Yamamoto  4mm rubber with Kevlar panels in high wear areas and titanium layers for added warmth. Because I dive and travel a lot and use my suits hard, I also opted for a heavy-duty zip, neoprene neck seal and a pee zip for those cold winter days when working from a small open boat and doing multiple dives means you don’t want to take your suit off between dives!

Something else to keep in mind when choosing a drysuit is aftersales service; a good quality drysuit should last you 10 years or more and over that period you will probably need the odd cuff or neck seal replaced, so being able to drop your suit back to the manufacturer for repairs or customisation locally rather than having to send it overseas is a big plus (and another reason I like Oceandry).

Carpet shark resting in a Caulerpa bed.

Carpet shark resting in a Caulerpa bed.

So far I have only tested the new Oceandry HECS drysuit out at the Poor Knights, where it has proved to be the warmest, most comfortable drysuit I have yet owned, but over the next couple of winter months it will be getting tested hard, with assignments to film ‘difficult to approach’ marine species both in the far south of New Zealand and in some really cold Northern Hemisphere waters!

NB: “There are only three types of divers: those who have a drysuit; those who secretly want a drysuit; and those who don’t dive in winter”! … Don’t be a diver who doesn’t dive in winter!


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