Laden with technical jargon and complicated terminology, sometimes it feels as if you need physics, meteorology and political science degrees just to understand the America's Cup. Now, with the 34th edition of the Cup being sailed in complex, hi-tech wingsail catamarans, there seem to be even more technical terms for punters to get their heads around.
The Herald has compiled a glossary of terms to help those of you who wouldn't know an AC72 from a B52.
AC72
the name of the class of yacht used for this year's America's Cup - 72ft wingsail catamarans. They're pretty special and ridiculously fast, capable of going over 90km/h.
Apparent wind
the direction and speed of the wind felt by the crew on board. A combination of the true wind and the motion of the boat. For example, if you're sailing at 25 knots upwind into 20 knots of wind, the apparent wind would be over 40 knots or "bloody strong" as Team NZ weather guru Roger "Clouds" Badham would say.
Auld Mug
The affectionate nickname for the America's Cup - sailing's most prestigious prize. The 162-year old trophy compels billionaires to sink large chunks of their fortune into a boat race.
Bearaway
To turn away from the wind. The top mark bearaway, where the boats transition from upwind to downwind, is one of the trickiest manoeuvres in the race for this year's event, and is known as the "death zone". When a really fast boat bears away, the apparent wind increases hugely, putting a massive load on the sails and foils and the boat accelerates.
Code zero sail
A cross between a genoa and an asymmetric spinnaker, used to sail close to the wind in light air. Used only when the wind gets below 12 knots, they came out once during the Louis Vuitton finals and we're unlikely to see them in the America's Cup match.
Delta
A fancy word for margin or distance (in time) between the two boats at each mark.
Ebb tide
Outgoing tide.
Flood tide
Incoming tide.
Foiling
Not a new concept, but new to America's Cup sailing. The AC72s have foils mounted under the hull. As the craft increases its speed the hydrofoils lift the hulls out of the water, greatly reducing the wetted area, resulting in decreased drag and increased speed. On foils these boats can achieve speeds of more than double the wind speed.
Foil to foil gybe
When the boat remains up on foils right the way through the gybe, significantly limiting the speed loss in the manoeuvre. But what's a gybe? Ah, pleased you asked ...
Gybe
(Sometimes spelt jibe) - the act of turning a sailboat across the wind downwind.
Jib
A triangular stay-sail that sets ahead of the foremast.
Leeward
Also known as lee, leeward is the direction opposite to the way the wind is currently blowing (windward).
Oracle Team USA
The bad guys.
Pitch pole
Very bad news. The most common way a catamaran can capsize, where the bows dig deep into the water and the boat "trips over itself".
Tacking
The act of turning the bows of the boat through the wind on upwind legs.
Team New Zealand
The good guys.
Tidal relief
When the current is flowing strongly on the race course, you'll see the boats heading to certain sections of the course - often close into the shoreline, or in behind Alcatraz Island - where the current is not as strong to get relief from the tide.
Trampoline
The netting that joins the two hulls that the sailors clamber across to get from one side of the boat to the other - some more elegantly than others.
VMG
Stands for velocity made good. How quickly you are progressing down the course. A true measure from point A to point B. The concept is useful in sailing, because a sailboat often cannot, or should not, sail directly to a mark to reach it as quickly as possible. Sailboats cannot sail directly upwind, and it is usually less than optimal, and sometimes dangerous, to sail directly downwind. Instead of sailing towards the mark, the helmsman chooses a point of sail that optimises velocity.
Windward
The direction in which the wind is currently blowing.
Wingsail
The giant, 40m-tall wingsails are what power the AC72 catamarans. Wingsails are similar to conventional sails, however a wingsail is a built-up mechanical structure with airfoil cross-section, like an aircraft wing, which can be shaped to provide a much better lift-to-drag ratio than conventional soft sails
- by Dana Johannsen in San Francisco
