OPINION by AUT's Sailing Professor Mark Orams:
After watching the first America's Cup practice day I feel compelled to make a 'public safety announcement'.
We have never seen boats this fast on our harbour before, and it was clear to me that some of the 25 or so spectator craft did not realise how quick they are, and the angles they work at.
There could be tragic consequences, in the blink of an eye, if something went wrong.
Even the very few powerboats which can travel at over 40 knots are not fast enough to escape from a potential collision with an AC75 in full flight, when you consider they can go over 50 knots.
Any vessels in the vicinity of these AC75s must be vigilant and give the teams huge amounts of space.
Apart from the sheer speed, they have other features which raise the risk of collision.
The sails are sweeping the deck so there is zero visibility through them to the other side. In addition, the sailors are located low down out of the wind giving them limited vision.
The use of the canting foil arm and foil wings to provide stability is often precarious. In wind changes such as puffs and lulls, the helmsman needs to make major course changes to keep the flight stable. They have few options if they are to stay in control. These rapid changes of speed and direction are hard to predict, especially in puffy winds.
Marshals and "no-go" zones will ensure safety during the formal racing, but they will not be in place as increasing numbers of spectator boats head out over the next couple of practice days.
Here are some safety rules if you are going on the water to watch:
1. Never cross (or try to cross) in front of the path of travel of an AC75 when it is flying. Their speed is such that they will be on top of you before you know it. Stop and watch from a distance or, if you are needing to move, make sure you choose a course which takes you behind their flight path.
2. Remember that these yachts turn and accelerate very quickly. Understand where the course area is and that the sailing area is diamond shaped from start line/box to top mark/gate. Stay outside of the diamond.
3. Do not crowd the start box area. This area is the most challenging for the crews to negotiate and manoeuvre in. The risk of over shooting a boundary or a higher risk turn being forced or needed is greater in this area.
The excitement is growing as the racing draws near. But let's stay safe out there.
Professor Mark Orams is the Dean of the Graduate Research School at Auckland University of Technology and is a former member of Team New Zealand. He was also part of Sir Peter Blake's winning Whitbread around the world yacht race crew aboard Steinlager 2.
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