Crossing The Mighty Manukau

The Manukau Harbour has a fearsome reputation, many souls having departed this world in its waters.

This record which stretches from the 1830s through to January 2010 when a five metre runabout was rolled while trying to back out of an intended bar crossing and a prison officer on board was killed.

In September this year the coastal freighter Spirit of Resolution grounded on the harbour's shifting sandbanks.

It is undoubtedly a place where care needs to be taken, where foolish, inexperienced or alcohol-fuelled sailors will quite probably find trouble.

It is also a very productive harbour and the waters just outside the heads and up the coast towards the deep water Kaipara Trench hold everything from marlin and mahimahi to hapuka and bass, along with giant snapper and kingfish, oversized Kermadec kahawai and the biggest gurnard you'll find anywhere.

The key is preparation, going when easterly winds have flattened the swell or at least straightened it out and smoothed the waters, and learning to read the waves.

The bar is constantly changing. The west coast sand is black because it is volcanic burn-off from Taranaki, driven north by constant current. The Tasman Sea produces wind-driven rollers of five metres and more. The prevailing sou’ westerly wind turns this to mush. The mouth of this massive harbour is just 1800m wide, from the tip of the Awhitu Peninsula to Paratutai. Of the 394 square kilometres, nearly one-third is exposed at low tide.

Tidal variation low-to-high can be as much as four metres.

Combine all these conditions and you end up with what the locals call "the washing machine", breaking rollers with white-tops of a metre or more, coming at you from four directions - swell-driven, wind-driven, tidal-driven and then rebounding off the sandbars and sharp cliffs that drop to the entrance.

Cornwallis, just inside Puponga Point on the northern side of the harbour, was designated by early city planners as Auckland's centre. But by the 1840s they had reversed that decision and centred Auckland City on the Waitemata Harbour, despite that meaning ships had to take a longer route around North Cape.

This was purely because of the number of shipwrecks. And despite that, New Zealand's worst maritime disaster occurred on February 7, 1863, when the Royal Navy steam/sailship HMS Orpheus carrying troops to fight in the New Zealand land wars was rolled after taking the wrong course and grounding on a sandbank. Of the 259 on board, 189 died.

Accidents since include the swamping of the boat Tobamoray in March 2005, sunk by a five metre wave, the inquest finding the boat had insufficient reserve buoyancy and that what buoyancy compartment there was allowed water in. One man died, two survived.

On January 9, 2010 four mates headed towards the bar intending to make the crossing. The washing machine was doing its thing and they decided to back out. But they did it the wrong way.

The boat flipped at approximately 8am but Coastguard were not notified until around 3.40pm, when someone on shore spotted the upturned hull.

Coastguard search and rescue coordinator John Cowan said the men did not notify the organisation that they were about to cross the bar. They did not have waterproof communications equipment aboard and were unable to call for assistance.

Their mistake was to try and turn in the washing machine. The wave and wind action creates foam and air bubbles near the surface, which results in propellers not being able to grab the water, known as cavitation.

Once you make the decision to go over the bar it definitely pays to carry on straight into the swell; if it's dodgy, go out and turn back in, running straight with the swell.

Another commonly made mistake is on return, skippers throttling so as to sit in the trough between waves. You will have more control, and more time to rectify any problems, if sitting right on the backside of a forward-travelling wave. You can choose your time to scoot over it once the whitewash has subsided.

Manukau Coastguard president Peter Van Rooyen says call-outs number between 20 and 30 per year, with around 120 people helped or rescued, down considerably on the average 120-per-year incidents that that used to be the case.  

"The fall in incidents must be attributed to the educational programs provided by Coastguard Northern Region and the fact that there seem to be a tendency for people to take better care and maintenance of their boats now," Peter told NZ Fishing World.

"The majority of the incidents, probably 80 percent, would be simple break downs such electrical, mechanical and fuel related, 10 percent involve assisting the NZ Police with shore line searches and the remaining 10 percent involve incidents over the bar, many of which are also mainly electrical, mechanical etc.

"Most are caused through negligence and lack of knowledge."

He is rightly proud of the organisation's rapid response times and a very good record for successful rescues without fatalities.

Peter's comments on lack of knowledge and preparation are borne out by comparison between the January fatality and a remarkably similar incident that occurred in the same spot a couple of weeks prior to the death. A boat with four men on board was overturned in the bar crossing area.

"Fortunately the vessel concerned was well equipped and the skipper had followed standard safety procedures. He had informed Coastguard Radio of their intention to cross the Manukau Bar, what channel they were crossing and how many people were on board. They were in radio contact with Coastguard Radio when they found themselves in difficulty."

All Coastguard units are on a pager system and on call 24/7, 365 days a year and when the pager went off for this incident it took 35 minutes to reach the stricken vessel in the south channel at the Manukau Heads. All four were picked up without injury. Coastguard routinely tries to salvage stricken vessels too because they can be a hazard for other shipping but in this case the anchor had dropped by itself and held fast so the upturned hull could not be towed. It washed up on Muriwai Beach three weeks later.

Manukau Coastguard have had their own dramas on the bar. Recently, a training exercise left one member with a broken leg and another suffering

concussion when their rigid-hull inflatable was twice pitched from the top of waves estimated at five metres.

The Manukau, Papakura and Waiuku Coastguard groups combine to hold a Bar Crossing Awareness Day twice a year to instruct and inform members of the public who intend crossing the Bar on the dangers and what to look for.

"There are a few very important procedures a boatie needs to follow before crossing a bar and they are: check the weather, check the swell height. Tell someone what your intentions are," Peter explained.

"Most importantly, file a trip report with the Coastguard at frequency "81" or the general Coastguard channel "16" on the VHF band. They like to know when you are about to leave harbour, to hear again when you have successfully completed the crossing, and vice-versa on the way home.

"Make sure you are on the correct radio channel and most importantly of all wear a life jacket. If you have a hand held VHF, strap it to your arm. If you can afford a personal EPIRB all the better.

They do not advise use of the northern channel, which has closed down to within a few metres in some places and, in wind-against-tide situations can be extremely ugly. The south channel is known to move widely after the regular storms that lash the west coast.

For a first-time crossing you cannot beat local knowledge and it is wise to either let a local drive your boat or at least to follow one out the channel. The Manukau Cruising Club, the Manukau Sportfishing Club and the Laingholm and Huia Fishing Clubs all have numerous members who have completed the crossing multiple times and if you intend to become a regular bar-hopper it would be a good idea to join one of these.

Personally, I won't go over the bar unless the wind has been blowing nor’ easterly for a few days and similar offshore conditions are expected during the trip. I've seen the swell go from one to three metres in the space of a day. If it's smooth that is a big enough problem - if it's wind-driven slop with the top third of the waves breaking, you're in big danger. I've also seen days so calm we stopped on the bar itself and caught 10kg snapper in three metres of sandy, dirty water.

They are numerous between 35-50m as are gurnard up to 2kg. From January-April the seas can be alive with albacore tuna and many westies gather these and salt then freeze them to provide months worth of great snapper bait. Behind the albacore are large yellowfin and striped marlin, sometimes in huge numbers.

Multiple strikes can be common in the blue-purple waters of high summer. And in recent years there have been increasing numbers of mahimahi too at this time of year - simply find any floating attraction like logs or weed mats and the dolphinfish will be beneath it.

Just remember Rule Number One: "If In Doubt, Don't Go Out."

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