September 2023: Risk of navigation using autopilot, and safe boating reminder

This insight highlights the risk of relying on autopilot for navigation and the importance of personal flotation devices, EPIRBs, and safe boating practices.

This investigation insight is for

  • Skippers, owners and operators of recreational boats and charter fishing vessels.
  • Maritime NZ maritime officers, investigators, and technical advisors.


In December 2022, a 5.5 m recreational aluminium power boat with four people on board capsized about 10 nautical miles off Cape Brett, Northland. The boat was returning from a day’s fishing as the sun was beginning to set. It was travelling at about 7 knots with lures out, in a 1.5–2 m swell.

The boat was on autopilot, which was set on the lowest responsive setting. As it reached the bottom of a swell, it suddenly turned hard to starboard, broaching and capsizing in a matter of seconds after water came over the port gunnel. All of the crew surfaced, although one crew member was briefly trapped under the hull.

The EPIRB self-activated in the water, and a crew member was able to retrieve it from under the hull so the strobe light could be seen. A local vessel rescued the crew, who were clinging on to the upturned hull, about 90 minutes later. By the time they were rescued, it was dark and there was a 23 m swell with 20 knot winds.

Following the investigation, the skipper was prosecuted and fined under the Maritime Transport Act 1994.



Maritime NZ found that a number of factors contributed to the event:


The boat was on autopilot in a following sea. It is possible that the boat turned suddenly and capsized because the autopilot over-corrected. Some small vessels, especially those under 6 m, can be compromised by autopilots in a following sea. Skippers with an awareness of this steer by hand rather than relying on autopilot.


The crew, including the skipper, had been drinking beer during the trip. Drinking alcohol increases the risk to safety, especially in an emergency, because it is a sedative and impairs decision-making, coordination and reflexes. In the water, an intoxicated person is more susceptible to hypothermia.


The ballast chamber was open, meaning the ballast chamber was not retaining water. A full ballast chamber would have made the boat more stable and less likely to capsize, especially in a following sea.

Personal Flotation Devices

None of the crew were wearing Personal Flotation Devices (PFDs) during the day or at the time the boat capsized, although they were available on board. Wearing PFDs was required by:

  • Maritime Rule 91.4(6), which requires PFDs to be worn on recreational craft in situations of heightened risk (for example, the distance the boat was from shore, the swell size, running with a following sea, alcohol consumption, and the empty ballast), and
  • Northland Regional Council Bylaw 2.1.3, which requires lifejackets to be worn at all times on boats 6 m or less in length.


The fading light and distance from shore made rescue conditions difficult. If the EPIRB had not activated and been retrieved from under the hull, rescuers may not have been able to see the strobe light and find the crew.


Safety reminder

Do not rely on navigation by autopilot

Steering by hand gives you greater control over the boat than relying on autopilot. In a following sea, actively steer by hand so that you can anticipate the movement of the boat and take corrective action earlier.

Avoid alcohol

Intoxication reduces reaction times and chances of survival in the water. When out at sea, it is important to stay alert as conditions can change quickly.

Use ballast water for stability

A full ballast chamber helps increase vessel stability and reduces the chance of capsizing.

Wear a PFD

Wear a PFD, as in an emergency or capsize there is no time to find one and put it on.

Be aware that:

  • local bylaws may require you to wear a PFD
  • Maritime Rule 91.4(6) requires PFDs to be worn on recreational craft in situations where tides, river flows, visibility, rough seas, adverse weather, emergencies or other situations cause danger or a risk to the safety of person on board.

We recommend wearing a PFD at all times when on board.

Carry an EPIRB on board

EPIRBS are invaluable in an emergency as they let rescue services know where you are. An EPIRB could save your life. A reminder that your EPIRB must be registered.


Remember, it is an offence to operate a boat in a manner that causes unnecessary danger, under section 65 of the Maritime Transport Act 1994.


More information

Maritime NZ – Recreational Boating:

Register your beacon:

Safer boating – Kia Mataara:

Maritime NZ Safer Boating Guide:

Standard drink calculator:

The effects of alcohol on boating:


Contact us for more help

If you have any questions about this investigation insight, please contact our Wellington office.


New Zealand (toll free):
0508 225 522

Calling from outside New Zealand:
+64 4 473 0111

Tell us what you need help with and remember to include your contact details (email address and phone numbers).