To pull this off, officials needed to restrict the boundaries. They wanted to keep the boats in close, which meant artificial boundaries were needed for the boats, just like with football where players have to stay within the field of play.
These “electronic boundaries” are not visible by umpires on the boat or by the racers themselves, so Milnes and his team provided the racers with a display on each boat that told them how far the boats were away from the boundary. There’s a countdown clock that as they’re sailing toward the boundary it essentially starts counting down from 200 metres, to 150 metres, 100 metres, etc. If it reads zero, the boat is out of bounds and receives a penalty.
In order to precisely track these catamarans—to assist both the racers and the television producers—and to assist the race officials, the instrumentation providing the navigation and providing the processed data, needs to be spot on.
“The way that penalties get assigned is all this data, the position data, the attitude of the boat, gets sent back to our control center and the umpires have a moving map display of where the boats are,” Milnes said. “Then the computer software also alerts them if they go out of bounds.” For the America’s Cup series—including the World Series races that lead up to the Cup—
there are two umpires in the booth, on shore, looking at their software, and two more umpires on the water.
“You still need people on the water. If boats touch it’s a violation. If they miss each other by a millimetre it’s not a violation,” he said. “So you really have to have someone on the water looking at these very fine details. Plus there’s issues of intent, you know if there’s a collision. Then you’ve got to decide whose fault it is. So giving that we’re umpiring the races that puts high demands on the navigation, and the reliability of the navigation because it’s part of the rules.”
Umpiring the Race
Now, race umpires are able to consult live computer-rendered diagrams showing boats and the location of different course markings before ruling on a possible rule violations, in much the same way that referees in American football now use instant replay. One big difference Milnes said, is that America’s Cup umpires will look at the images before making their calls.
The 34th America’s Cup finals feature 72-foot boats called AC 72s. The World Series uses different, 45-foot boats called AC 45s. This year, during the 35th America’s Cup 50 foot AC50’s will compete. Working these events means plenty of travel, so Milnes and his colleagues have worked in the UK, France, Portugal, Japan, San Diego, Chicago, New York, Sweden, and Italy in recent years, before heading to Bermuda this summer for the 35th America’s Cup, often referred to as “The Match”.
“Throughout all of these races we have NovAtel instrumentation on the boats,” said Milnes, whose team has been through four generations of hardware since first implementing the technology in 2001 in NASCAR, as NovAtel has continuously improved its receivers.
“We’re always improving our software but for the most part we’re using the original hardware that we purchased in 2011 for the America’s Cup. It’s been good and reliable. It’s certainly been well received and everyone seems to like what we’re doing, by all means,” he said.
The TV graphics are always improving. To ensure reliable GPS corrections, they set up their own differential base station, along with a Wi-Fi network to allow communication with the boats between ship and shore.
“Then by using the differential corrections we get centimetre level position accuracy,” he said. “Now with knowing the heading and the attitude of the boat, we know where all parts of the boat are. Our GPS receiver is back on the stern of the boat, and on the AC 72s, for example, the bow is, you know the front of the boat is 72 feet in front (of the receiver).
“With our TV graphics, we put a national flag to identify the boat at the top of the mast. On the AC 72s that mast is 40 metres up in the air. We need to know the pitch and roll of the boat so we can place the flag graphic at the top of the mast. So the fantastic accuracy of the NovAtel equipement and SPAN technology is just vital. This wouldn’t work without that.”