It takes just under an hour to reach the Reef, depending on conditions and boat size / speed. GPS Coordinates for Astrolabe Reef are 37° 32.439’ south and 176° 25.692’ east.

Boats less than 5m in length are not encouraged to visit the Reef for safety reasons. Learn more about general safety information, marine broadcasts and other useful information, including Maritime New Zealand’s Skipper Responsibilities information.

If you haven’t visited Astrolabe Reef before, it is strongly recommended that you speak with one of the local fishing, boating or dive retailers or clubs as part of your planning, or join an organised trip so you are in good company. 

For people intending to dive, it is important to understand that Astrolabe Reef is a technical, open ocean site with depths beyond recreational diving limits. 

What to Expect Onsite

There are a number of potential and significant hazards that visitors to the area should be aware of.

The tip of the Reef is a rocky pinnacle which rises up 75m from the surrounding seabed, breaking from the surface at low tide. The Reef has varied underwater topography including gullies, plunging walls, shelves, caverns and caves. The Reef is regularly subjected to a prevailing strong northerly swell, currents are unpredictable and wind conditions can be strong and change rapidly (particularly the prevailing west and southwest winds).

WRECKAGE LOCATIONS

The Rena wreckage is fully submerged and poses no risk to navigation. It occupies less than 2% of the total Reef area, and can be categorised into three parts of wreckage the bow section, separated bow pieces and the stern section. The bow section and the separated bow pieces are marked as dive sites 1 and 2 but it is NOT recommended that the stern is dived due to its depth.

Mooring buoys of the different parts of the wreck are maintained by the local dive club but may be absent after periods of heavy swells.

Astrolabe Reef and the location of the wreckage (March 2015].

ASTROLABE REEF BUOYS

BIRD'S-EYE VIEW OF WRECKAGE and dive sites 1 & 2

Safe Boating Reminders

  • Always check the marine forecast before setting out.

  • Vessels less than 5m in length are not encouraged to visit Astrolabe Reef due to the conditions being unsuitable for small boats.

  • All vessels should carry a 406MHz EPIRB (Emergency Position Indicating Radio Beacon).

  • Ensure you have enough life jackets / flotation devices of the right size for everyone on board. Wear your life jackets at all times.

  • Inform someone onshore of your trip, including your return time.

  • Skippers can report trips to the Coastguard on Channel 83.

  • Boats with divers in the water must fly an A Flag (diver’s flag). This must be 600x600mm minimum in size and divers must remain within 200m of this dive flag.

  • No person shall propel or navigate a vessel (including a vessel towing a person or an object) at a speed exceeding 5 knots:

    • Within 50m of another vessel, raft, floating structure, or person in the water; or

    • Within 200m of any vessel or floating structure that is flying an A Flag of the International Code of Signals (diver’s flag).

A Flag

A Flag

Helpful Boating Information

HOURLY MARINE FORECASTS

  • VHF Channel 83 – Coastguard broadcasts hourly marine forecasts.

  • SeaComs channels 3 and 24 are used by many local skippers.

  • VHF Channel 6 is also used by local skippers.

MARITIME DISTRESS AND EMERGENCY CALLS

  • VHF Channel 16 is the international channel for maritime disasters and hailing (calling).

  • Dial 111 in the case of an emergency.

NOTICES TO MARINERS FOR THE AREA

HARBOUR MASTER CONTACT DETAILS

Astrolabe Reef – Otaiti – Access Guidelines (for Download)

The following booklet and flyer are available for download and reproduction. The documents were prepared as part of an access plan ahead of public access to the Reef being restored. They have been widely distributed to various groups throughout the Bay of Plenty region.

Distress, Urgency & Safety Calls

Special calls are used in distress, urgency and safety, and must be properly understood and used correctly.

Use VHF Channel 16 to make a call.

DISTRESS:

The radio-telephone distress signal MAYDAY is used to indicate that a vessel, aircraft or person is in grave and imminent danger and requires immediate assistance.

URGENCY:

The radio-telephone urgency signal PAN PAN is used to indicate that a vessel has a very urgent message to transmit about its safety.

SAFETY:

The radio-telephone safety signal SÉCURITÉ (pronounced say-cure-ee-tay) is used to indicate that the calling station has an important navigational or meteorological warning to transmit.

FISHING:

Ōtāiti is part of the Motiti Protection Area and fishing is prohibited. This applies to everyone, including customary, recreational and commercial fishers, divers & those spearfishing , even if your are catching & releasing.

DIVING:

Diving the wreck’s stern section, marked with yellow buoys, is NOT recommended due to the depths at that location, except for qualified PADI technical divers.

Astrolabe Reef has always been regarded as an advanced dive site, therefore divers wanting to inspect the wreck site are encouraged to dive sites 1 and 2 only – marked by the orange buoys. 

It is also strongly recommended that people wanting to dive do so with a local dive club or dive charter operator. 

Do NOT attempt to dive the wreck unless you have the right experience, training, equipment and fitness. Divers should hold, as a minimum, a PADI Open Water certificate and be suitably experienced for an advanced dive site like Astrolabe Reef. 

Skippers can moor at the orange mooring buoys while divers are in the water. If all moorings are occupied, then vessels can either ‘raft’ to other vessels in appropriate conditions or wait until a moored vessel has moved off. If the Reef is particularly busy consider returning later or even another day.

BIRD’S-EYE VIEW OF WRECKAGE AND DIVE SITES 1 & 2

BIRD’S-EYE VIEW OF WRECKAGE AND DIVE SITES 1 & 2

astrolabe reef buoys

astrolabe reef buoys

Diving is an inherently risky activity and wreck diving has a number of specific risks to be aware of. It is important that divers follow these recommendations:

  • Divers are encouraged to dive the two dive sites marked with orange buoys (see illustrations below).

  • Ensure your boat is flying an A Flag (dive flag) and stay within 200m of the flag.

  • All divers must carry a whistle, inflatable safety sausage or similar device to alert your skipper to your whereabouts on the water’s surface.

  • Due to the strong currents, plan to be collected by the skipper immediately following your ascent and hold onto the float line while waiting.

  • Always dive with a buddy and adhere to safe diving practices, including planning your dive and diving your plan.

  • Check the currents, including their strength, before entering the water. Anything greater than 1m in swell, 1 knot of current and / or 15 knots wind is considered unsafe for diving.

  • Water temperatures generally range from 20-22° in summer and 12-13° in winter. Due to water clarity and the gradual incline of wreckage, judging depths can be difficult. Take care not to exceed your safe depth.

  • Be aware of potential snagging obstacles and always carry a knife.

  • Do NOT remove cargo or objects – some may be heavy and compromise your ability to resurface safely.

  • Safety stops at -5m have been marked on each buoy line – these should be used for your ascent but not relied upon.

  • Snorkelers should have an A Flag attached at all times.



DIVE SITE 1

This site is marked by an orange mooring buoy at the outer bow piece, with the label ‘Dive Site 1 -18m’.

It is an advanced dive site due to depth, but is in an area subject to less surge as it is in a sheltered section of the Reef.

Divers can explore the separated bow pieces (including the bow thruster) by descending at the buoy down the shotline. Head northeast following the wreck pieces along to the next piece, with the Reef wall on your right-side. Here you can explore the marine environment in the natural gullies, then return to ascend the same buoy.

A safety stop marker at -5m on the buoy’s shotline should assist divers with their ascent, but it should not be relied upon.

DIVE SITE 2

This site is also identified by an orange mooring buoy, with the label ‘Dive Site 2 -14m’. Due to its location near the peak of the Reef, it is in an area subject to greater surge that divers should be aware of.

The dive is set into three loops, with each trail beginning and ending at the shotline. Divers are encouraged to follow the order of trail 2A (deepest first), followed by trail 2B, and finally 2C. Please note that you may not be able to complete all three trails in one dive.

Trail 2A ‘The Wall’: From the shotline follow the topography on a decline with the Reef wall on your left side until you come upon a piece of wreckage that is not illustrated in the Dive Site 2 image, but at 0:46 minutes into the Dive Site 2 video you can see it. From here, return on the open side of the wreckage and loop back with the Reef wall on your right to the shotline.

Trail 2B ‘Double Bottom’: From the shotline head south as the depth drops down into a bowl. Ignoring the topography, swim at a depth no more than -18m until you come across the double hull section which is laying against the southern face of the Reef. There are many crevasses to explore within the Reef structure. At the double bottom hull section, traverse the wreckage and head north towards the shotline.

Trail 2C ‘Bow Structure’: From the shotline head northwest following the topography upwards with the Reef wall on your right. Rising up the Reef you will eventually see the section of bow structure. Subject to conditions, aim to swim around the structure in an anticlockwise rotation (keeping the wreckage on your left), before following the topography back down toward the shotline.

Divers should return to the shotline to ascend. It is also marked at -5m to help divers conduct their recommended safety stops.