03 August 2022
Catering for vessels between 12 and 30 metres length overall, the 181-berth Kennedy Point Marina (KPM) on Waiheke Island is almost fully subscribed, with only a handful of larger sizes now available.
Though the COVID pandemic created enormous logistical challenges and severely disrupted construction, the project also resulted in a number of unique build strategies and New Zealand construction firsts.
“While floating wave attenuators have been used in a number of New Zealand marinas, this is the first time they’ve been used on this scale,” said Project Manager, Scott Fickling.
“Traditionally, marinas have used rock-pile breakwaters which can affect tidal patterns and interfere with ecologically sensitive environments.
“A floating breakwater, by contrast, allows for a natural, unencumbered twice-daily tidal flushing of the site and is widely used here and elsewhere in the world. The relatedly deep water throughout the marina basin at KPM also lent itself to floating structures.”
The floating design is the brainchild of Swedish-based company SF Marina Systems AB, with coastal engineering design support from three different continents.
KPM uses 23 pontoons forming two, separate attenuation breakwaters. Each pontoon measures 20 x 6 x 4.2 metres and weighs over 200 tonnes.
“We initially envisaged shipping the completed units from Sweden,” Fickling continued. “But that was a daunting prospect and having them built locally would benefit the local economy.”
To that end, Whangarei’s Heron Construction entered into a manufacturing license agreement with SF Marina and developed a purpose-designed site for producing the mammoth units.
It’s an intricate process – each pontoon requires 23 truckloads of concrete and must be formed in a single, uninterrupted pour.
Getting the completed units to the Waiheke site presented an additional challenge: each pontoon is launched into the sea and towed 90 miles to the island by tug at a sedate two knots, a voyage that’s very weather dependent.
About half of the pontoons are already in place, with the last to be manoeuvred into position in September this year.
Each pontoon is secured in position with two, 35-metre-long steel piles, driven through the pre-cast pile guides from above using temporary construction barges and some of the biggest piling equipment in operation in New Zealand.
Installing the marina berths – piles, fingers and piers – will be tackled once the attenuator structures are complete. These components are being built by Glendene’s Total Marine Services Ltd.
“About 20 percent of the structures have already been cast and start arriving on site in October,” said Fickling. “Stockpiled on a large barge, they will be lifted into position by crane. This construction phase should come together very quickly.”
Other key components of the project include a 72-spot carpark and a building comprising the marina office, services, a public cafe and a small boat launching deck.
As with the rest of the KPM design, these structures are built on floating pontoons, which rise and fall with the site’s 3.5-metre tidal range.
The office building is being built on its own pontoon structure and will be towed as a completed unit from Whangarei. The marina will also have wi-fi and each berth is equipped with 240-volt power and water.
Marina services and facilities will be provided to berths on a user-friendly interface with access via a swipe card and PIN. Users will also be able to use a smartphone app for access. The same card/technology applies to showers and the laundry in the marina building.
So, who bought the berths? “Aucklanders, a few out-of-towners, but mostly Waiheke locals who either live or have a bach here,” said KPM Director Sarah Mair, noting it was a mixed bag.
“While different factors are behind the rapid uptake, the acute shortage of marina berths in the greater Auckland region is obviously a major driver.
“We believe the destination marina concept also holds plenty of appeal – it’s the country’s only island marina and people keen to visit the island for a weekend break (or longer) want to have their boats in a secure berth.
“I think many will use the marina as a convenient base or launching pad for exploring the greater Hauraki Gulf.”
Thanks to seasonal fluctuation and the transient boating lifestyle of some berth holders, any vacant berths will be available to rent for short- and long-term stays.
The marina will also cater to visiting boaties in small runabouts – day-trippers who want to leave their vessel in a secure marina while visiting the island.
“There are dedicated pontoons on the edges of the marina which offer plenty of mooring spots for trailer boats,” said Mair.
“I think the facility will appeal to visitors who don’t want to be tied to the ferry schedule. There is also a public drop-off berth.”
Berths are sold with a 35-year license – a period tied to the term of the coastal occupation permit granted by the council.