Artificial Reef Unveiled in New Zealand

New Zealand’s first artificial surfing reef roared to life in Mid-December, producing some fascinating chest to shoulder high waves for local Mt Maunganui surfers.

A small (and rather soft) northeast swell generated from a close low and high pressure squash zone sent clean one metre swells to the Mt Maunganui coast. With the artificial reef’s large bags almost full and ready to go, the reef finally had a chance to produce some waves. Clean waist to head-high set waves peaked on the reef with some spectacular results.

A solid pack of surfers sat on the peak with body boarders dominating the left-hand break for most of the day. Most were pulling into deep barrels and occasionally making them. Stand up surfers were still coming to terms with the savage drop with many heading over the falls. It’s interesting, all these shots were taken as the reef broke on the mid to high out going tide – what will low tide, large swell and a stiff offshore produce?

The Wave

The waves produced by the reef were very short, sharp and at times spooky. The reef only broke with the larger set waves and featured long lulls between waves. Peaks built gradually and peaked over the reef often jumping at the last moment. Occasional double-ups produced some weird and spooky looking lumps of water, which added to the entertainment value for onlookers at Tay Street.

The wave featured a late drop, which transformed into a gaping pit and fast wall through to a fat wall/fadeout near the end. Estimated length of ride was around 20-40m.

These images you see here were captured over a two-hour time period – during that time only one surfer managed to link from the reef through the inside.

Surfers in the water reported a heavy double up after the initial peak. The Mount Reef team confirm this saying that two humps were formed in the large bag where the inlet valves for pumping in sand are located. These humps should flatten out once some large swells hit the reef.

Duck diving can also be a rough experience with many surfers being sucked up and thrown over the falls.

Dr, Kerry Black Interview

An interview with artificial reef construction expert Dr. Kerry Black

So how good is the wave, is it as good as the shots make out?

At this point it’s still too early to tell. The photo’s don’t lie, but also don’t capture the short length of ride. However, it is a rideable wave with consequence.

We must also take into account the nature of the swell on this day, which was quite soft and lacked power. The Reef most definitely has a personality all of it’s own. In it’s current state it will attract a lot of surfers who are looking for something a little different along with a good challenge. At lower tides the reef can become extremely shallow, the Mount Reef people tell us that it is quite possible that it could suck dry 15 metres ahead of the takeoff on big days at low tide. This will attract the thrill seekers who need a good thrashing over the falls and to spend a bit of time with a geotextile sand bag.

With solid clean groundswell conditions present, the reef looks as though it has the potential to work, if not work well, time will tell. Larger swells should also have more of chance to break further seaward and have the energy to link with the inside sections of the beach.

Improving and Finishing the Reef – What’s Next?

The ASR / Mount Reef Trust team have faced an unusual and rare challenge from the BOP waters during the construction of the reef – an abundance of swell. With the lack of southwesterly winds and abundance of northerly activity, this has meant a series of small northerly and east swells to contend with. The equipment and barge used in the construction process is extremely limited as far as operating when any swell is present. This has meant long interruptions to the schedule.

“It will only take a day or two to complete the filling of the smaller bags on the eastern side of the reef and to top up the seaward side of the big bags which are about 1.5m lower than the beach end. Another six days of perfect weather after that should see the whole of the western side of the reef completed and the reef finally ready to function as designed. We’ve been plagued with constant swell throughout, and even the smallest swell means we have to stop work and wait for it to drop”, said Mount Reef Executive Officer David Neilson.

"As it stands the reef’s three large geotextile bags are almost full, along with two of the smaller seaward positioned bags. Four smaller bags are still to be filled. Because only one half of the reef is in place, there isn't a focus at the start to gradually build and shape the waves. Instead waves are coming over the deep and shallow sections at the side causing the wave to break half way down the big bag at the humps. This explains why the wave currently lacks length of ride and shape", said ASR Ltd reef designer Dr. Kerry Black.

Construction is set to begin again possibly February next year with the finishing and filling of bags on the left-hander and construction of the right-hander. Having the whole reef in place will give it an opportunity to function as it was tested and designed to do.

“The reef was never designed to function as a single left-hand break. Once we have the whole delta shape in place the reef will offer a far wider window for multiple swell directions allowing certain swells to peel around either way. At the moment swells with a lot of east tend to slam head on into the left-hander rather than peeling down the bags”, says David Neilson.

The reef sea floor features a dramatic slope of 1.0 -1.5 metres on the seaward end of the bags. This is in conjunction with the under filled seaward end of the big bags is affecting the reefs ability to break a wave at the reef start. Filling the smaller bags near this end of the reef, topping up the large bags and putting in the right-hander should improve the length of ride dramatically.

The other interesting factor is the effect the reef will have on the sea floor between the reef and the beach. It is quite possible for a sand build-up to arise in the lee of the reef, again increasing the possibility that waves breaking on the reef will continue and link through to the beach providing rides in excess of 100m.

So, where to from here? Let’s just wait and see what happens once it's completed – time will tell.