Are you the best diver you could be? Qualified – Yes! Experienced – Yes! But are you Fit, do you Check, and do you always Signal? NZ Underwater’s 2019 signature message to divers applies to even the best of the best, and here’s why…


Do you ask yourself the question, ‘Am I fit?’ before diving. Being fit to dive requires more than the ability to swim a couple of lengths of the pool, it means physically and medically fit.

Water Safety NZ data collated since 2011 clearly demonstrates 60% of all fatalities in divers, spearfishermen, and snorkelers occur in the over 40s. Poor heart health and inadequate fitness is the significant factor in these diver deaths.

Dr Chris Sames of the Slark Hyperbaric Unit in Devonport, covered the complexity of the issue in our 2018 interview Diving over 40? Why a medical check-up might save your life.

“If you’re fit, you’re less likely to get into trouble.”
Diver medical checks
Routine medical checks are a diver's best friend
In summary, the question of dive fitness is covered by three primary considerations:

The Age Factor – The heart’s capacity to support the elevated blood output required by diving decreases with age. Maintaining a healthy heart is of the utmost importance to your safety while diving

Prescription Medicines - Some common medications such as beta blockers or anti-arrhythmia treatments can increase cardiac risk while diving. Consult your doctor before diving and consider a prescription change if so advised.

Depth Compression – As a diver descends, the heart rate slows to conserve oxygen and the lungs compress. Older divers are well advised to be conservative with dive depths. Improving general fitness, particularly heart health with a committed cardiovascular workout programme, will enhance your ability to cope with stresses of depth and water pressure. The same rule applies to spearfishermen.

In Dr Sames’ words, “If you’re fit, you’re less likely to get into trouble.”


Routine pre-trip checks trained on dive courses and recreational boating qualifications, like Coastguard’s Boatmaster have been crafted and refined over the years to give you the best chance of averting an issue before it happens.

A simple checklist in timeline sequence is offered as follows:

Check the weather

• Is the weather forecast, including swell height and wind speed, appropriate for the activity?

• Is the weather forecast also suitable for the boat size

• Consider the tides and avoid locations known as tidal hot-spots during peak flows and during king-tide periods

For information on understanding weather forecasts visit

spearfishermen should use dive markers

Check the boat – Is it sea-worthy?

• Get the engine serviced,

• Check the fuel levels (replace old fuel as it may be unreliable)

• Check the batteries

• Give it a good visual once-over looking for issues of wear-and-tear

Maritime NZ offers best-practice advice on this subject.

Check your safety gear

• Are the lifejackets up to scratch? Old-school kapok jackets should go in the bin, replaced with new

• Do you have two forms of working communication - VHF plus one other

• Have you filed a trip-report with family/friends and with Coastguard?

Check your dive gear

• Test and inspect every item to ensure it is functioning correctly

• Check for any relevant inspection dates on equipment such as dive tanks (annually) and regulator stages

• Ensure tanks are full and that the air is 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

• Once kitted up, is everything functioning correctly

Read more about gear maintenance

Dive buddy gear checking
Check your buddies gear, as well as your own.

Check your dive buddy

• Is he or she in a fit state to dive?

• Is their gear in good condition and fully operational?

• Do they know the dive plan?

Read more about the Buddy System


Signal the trip

Trip reports may be the single most important and overlooked safety step a diver can take.

  • Record them with family or friends
  • Record with the Coastguard or local VHF monitoring service
  • Include – Destination, ETA home, Number of passengers on board, File passage/plan updates as necessary

Signal the dive

In most cases, including spearfishing and all forms of SCUBA, signalling your dive is a mandatory legal requirement. Fines can be issued on the spot with the potential of severe liabilities resulting from an accident investigation.

Signalling devices include:

  • Dive flags for vessels and/or land-based activities
  • Various inflatable and rigid surface floats
  • Tow-boats with flags for spearfishermen

Signalling your presence helps ensure the safety of all the trips participants, although personal responsibility should still prevail. Vessel skippers observing dive activity signalling are required by law to reduce speed to less than 5-knots within 200m of the signalling device.

Refer to the NZ Underwater Diver Down campaign for more information.

Diver surface marker device

Signal YOU

Numerous devices can be carried by divers to indicate their location on the surface or in distress circumstances:

  • Surface Marker Buoys - Various inflatable surface marker buoys can be deployed to inform boats of your ascending position, and as a clear and obvious marker of your location should current or weather conditions inhibit returning to the vessel
  • AIS - AIS-capable rescue devices recently entered the market, led by the McMurdo S10 Smartfind Personal AIS Beacon. Personal AIS works with any AIS-equipped vessel navigation system (increasingly common at the consumer level) to precisely locate the surfaced diver directly on the boat’s navigation screen. View the McMurdo S10 on Safety at Sea’s website.
  • Strobes
  • Strobes serve multiple purposes for divers – as signalling devices to divers underwater as well as being useful surface location devices.
  • Divers in distress on the surface of the water, particularly at night time.

About NZ Underwater

New Zealand Underwater is the country’s recognised leading not-for-profit organisation promoting and advocating safe and enjoyable underwater activities in a protected marine environment.

It’s three key areas of activity are as follows:

Environment: NZU is an advocate for clean sea programs, supporting environmental campaigns with volunteers and expertise.

Safety: NZU flies the flag for diver safety in New Zealand, managing essential services like the Dive Emergency number (0800 4 DES).

Underwater sports and participation: Many of our members are keen sports people engaged in scuba, spearfishing underwater hockey or snorkelling. Numerous affiliated clubs support these activities and welcome new members.

NZ Underwater Association
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