Ask Phoebe: ARC website keeps tabs on waterway markers

Where can I get the GPS co-ordinates for all harbour channel buoys and ARC harbour buoys? Also, why are the racing buoys not numbered?
Kevin Purcell, Castor Bay.

Visit www.arc.govt.nz, enter "racing buoys" and then click on Harbourmaster.

The pending Rough Rock racing mark has co-ordinates of 36 49.044S and 174 49.212E. There are also racing marks at Motukorea buoy and Motukorea beacon (36 48.705S 174 53.044E and 36 49.926S and 174 52.064E respectively). The co-ordinates of the Bayswater buoy (2) were not available.

The Salt Works, Flax Point and Orakei buoys are unlit, and the North Head, Torpedo and Stanley buoys flash yellow every five seconds.

The racing buoys are yellow and the shipping channel markers are red and green, red for port and green for starboard for vessels entering the harbour.

The shipping channel markers have their numbers on them, even numbers for port and odd numbers for starboard, but it has never been thought necessary to number the racing buoys.

I am intrigued by the large steel truss by the St Marks onramp, alongside the railway line, that seems to be supporting the motorway viaduct. Can you shed any light on this please?
Max Purdy, Remuera.

The steel supports are there to maintain the existing Newmarket Viaduct structure while it is being taken apart in stages, as part of the replacement project.

Individual supports will be installed on all the viaduct piers to help maintain stability during the deconstruction.

However, the St Marks onramp is now closed until 6pm on Sunday, July 19. Motorists should use the southbound Greenlane onramp instead. It's hoped that the disruption should not be too onerous as it is school holidays.

You can find out more about the project at www.nzta.govt.nz/newmarketconnection or by calling 0508 CONNECT.

The signs at motorway onramp lights around Auckland say "one car per green each lane". On some onramps, Ellerslie, for example, there are four sets of lights. When the lights are green does that mean that there should be two cars from each lane going? One car for each green light? Or does it mean one car per lane?
Kelly Nicholls, Auckland.

The Transport Agency says that when the ramp signals turn green, one vehicle per lane is allowed to proceed.

If there are two queues, then one vehicle from each lane goes on the green signal.