New Zealand Underwater is the country's leading voice in the essential area of diver safety, with efforts concentrated across three pillars

Training and Education.

The NZU actively promotes formal diving education from experience-based introductions to professional qualifications. Topics covered include:

  • First introductions to snorkel or scuba
  • Beginner and intermediate certifications
  • Instructor courses
  • Technical diving
  • Refresher courses

Best Practice on the water.

Educating active divers and aboaties on best practice requires on-going work across multiple media initiatives.

Emergency support.

NZ Underwater maintains a specialist emergency contact line for divers and provides analysis of incident data. 




If you have divers, spearfishermen, snorkelers or swimmers in the water it is a legal requirement to display a dive flag at all times.  The blue and white Alpha Dive Flag is an internationally recognised symbol used for this purpose.

The Dive Flag law applies to:

  • Divers
  • Spearfishermen
  • Snorkelers
  • Swimmers

The purpose of the dive flag is to let other water users know people are in or under the water near your vicinity.

The flag informs other boat users to keep well clear and move at a slow speed. All other boat users must maintain at least 200m distance from the flag or keep their speed to less than 5 knots.

The minimum legal flag size is 600mm high by at least 600mm long. It must be clearly visible from at least 200m away, even when there is no wind.

The Dive Flag should only be flown when people are physically in the water.

Spearfishermen, shore-based divers and other open water snorkelers are advised to tow a dive flag with them. 

Dive Flags for specific purposes can be purchased at most quality scuba and spearfishing retailers.

What does a Dive Flag say to other water users?

  •  There are divers, spearfishermen, snorkelers or swimmers nearby, possibly under the surface
  • SLOW DOWN! Your speed must be less than 5 knots when within 200 metres of a dive flag

Watch Your Position!

Stay within 200 metres of your dive flag. Plan your dive to stay  either close to the boat, or have a surface float (with dive flag) that marks your position for other vessels to take note of and avoid.

Remember, if people are diving, spearfishing, snorkeling or swimming off your boat it is your responsibility, along with the person in the water, to ensure the Dive Flag is being flown while they are in the water.

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Always dive with a buddy. The buddy system was developed and refined to dramatically improve diver's survival across a range of potential underwater incidents.

Buddy Diving Best Practice

Buddy Diving can save you during catastrophic gear failure, out-of-air emergencies, entanglement, disorientation including but not restricted to cave and wreck diving, and underwater medical emergencies.

As a rule, the buddy system applies to pairs of divers. Even when diving in groups, members of the group should always pair up. 

  • Both divers should be fit to dive the conditions
  • A dive plan should be formulated and agreed on including provisions for separation
  • All gear and equipment should be checked before entering the water
  • Both divers should be familiar with the operation of each other equipment
  • Both divers should be aware of their responsibility to assist the other diver in an emergency
  • Divers need to maintain a degree of contact throughout the dive
  • Divers should ascend together whenever possible
  • Always tell a third party about your dive trip - preferably someone shore-based

Find a Dive Buddy

New Zealand Underwater would be delighted to help you find a dive buddy. The best place to start would be to make contact with one of our member clubs.

Useful links:

NZU Member Clubs



As with any equipment exposed the marine environment, routine maintenance is an imperative part of a scuba diver's schedule. Gear failure can have severe and occasionally even fatal consequences.

Before every dive trip

  • test and inspect even item to ensure it is functioning correct
  • check for any relevant inspection dates on equipment such as dive tanks (annually) and regulator stages
  • ensure tanks are full and that air clean - never dive on old or stale air
  • inspect BCDs and dive suits for rot
  • test for perished silicone or rubber on masks, fins etc

After every dive trip

  • Thoroughly wash all gear in fresh water - prolonged immersion is preferred over hosing
  • Thoroughly dry all equipment - consider a hot water cupboard for electronics and items with moving parts
  • Store in a clean dry environment - consider air tight packaging with moisture absorbing pads for some equipment
  • Avoid storing sensitive equipment with wet-suits or dive bags for prolonged periods
  • Keep dive tanks full when not in use - this helps prevent internal moisture damage (you may need to refill with clean air if storage is for a long duration)
Note: NZ Underwater's commercial partner Air Purity provides experts in the field of clean air and gear maintenance. Visit or contact Air Purity directly for expert assistance if required.
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Safe surfacing procedures including safety stops, are an essential part of all scuba diving.

Allowing for a safety stop on all dives greatly reduces a diver's risk of medical complications resulting from dissolved gases in the bloodstream during the event and the long-term consequences of build up these gases during a lifetime of diving.

New Zealand Underwater advises planning for a least one three-metre safety stop on all dives, and as many more as are required by the technical details of a dive. 

A three-metre safety stop also allows the opportunity to look up and listen for any approaching boats.  

Note: Breath-hold divers do not have the luxury of a three-metre safety stop so always ensure an observer can wave a dive flag at any approaching vessel.



Are you dive fit?

Scuba diving as a leisure activity is accessible to people through many stages of their lifetime.

New Zealand Underwater always offers the same advice when contacted by divers looking to return to the water after a long hiatus —

  •  Be honest about your abilities and limits
  • Have a diving specific health check with a doctor and continue those checks on a regular basis. Heart attacks kill more divers than any other cause
  • Consider an official training provider supplied diving refresher course. Scuba diving practices and equipment have changed in 20 years and a refresher will get you up speed and make you a safer diver 
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Always check the weather and tide conditions in advance of departing of dock.

Numerous high quality weather and tides sources aid good decision making for the experienced skipper or guide. Pre-trip checks via the internet or other source should always be supplemented by up-to-the-minute information via a VHF radio.

Even in circumstances where independently neither the wind or the tide appears problematic to your dive these two natural forces can combine to produce a serious threat to diver safety.

Wind pushing against the tidal flow often produces dangerously unpredictable conditions for a vessel and for divers on or near the surface.  Wind running in the same direction as the tide can make it extremely difficult to return a vessel.

Experience is the key to anticipating the effect and specific set of weather and tide parameters with have on a dive location.

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