Mining the Numbers

Sailing from the seat of your pants will only get you so far. If you’re looking to go further, check out this new performance-analysis system adapted from the world of Formula 1 racing. "Electronics" from our September 2010 issue.

December 20, 2011
Sailing World

Pi Toolbox Output

A typical Pi Toolbox output for the Mini-Maxi Rán shows the level of analytic detail possible: tack speed, rudder angle, course track, and more can be synced with onboard video. Courtesy Cosworth Electronics

Most of us gauge our on-the-water performance by keeping tabs on the instruments, eyeballing our competitors, or simply being in tune with the intuitive feeling from the seat of our pants. But imagine if you could explore virtually every nuance of your sailing to the nth degree—sail trim, design, and selection, maneuvers, straight-line speed, rig-tune, and anything else thinkable. At present, grand-prix teams use expensive custom electronic suites to capture, deliver, and dissect data into mind-numbing masses of gigabytes, but a few top teams have also caught onto off-the-shelf performance-analysis tools transplanted straight from the asphalt-laden realm of Formula 1 car racing. These systems, now being used on dinghies to 100-foot, record-breaking trimarans, are giving sailors the tools to ratchet up their performance to a much higher level.

The Pi Research system from Cosworth Electronics (headquartered in England and a major player in the Formula 1 industry) has two core components: a small, lithium-ion-powered data logger and the Pi Toolbox sofware. The logger itself has an integrated accelerometer (like the device in an iPhone) that measures motion on a three-way axis and a GPS. Additional sensors feed data to the logger: for example, a laser sensor (to measure rudder angle), load cells (to gauge rig tension), video camera, and output from onboard instruments.

The business end, however, is the Pi Toolbox sofware, which allows clever (and committed) sailors to explore and analyze the data in as many ways as are imaginable. One navigator that knows this, perhaps too well, is Robert Hopkins, a veteran of the America’s Cup, and early adapter of the Pi system. For the past year, he’s been using it on Hap Fauth’s R/P 69 Bella Mente, and is a true believer in its potential.


“The whole purpose of buying and changing an instrumentation system is to be able to analyze things better,” says Hopkins, who admits to spending an exorbitant amount of time customizing the Toolbox sofware for Bella. “What the Toolbox lets you do is develop a series of views, reports, charts, and graphs. Once you develop them, you can easily reuse them.”

On Bella Mente, the boat’s electronics processor (B&G WTP2) continuously feeds the Pi logger data, as does an onboard camera mounted on the stern. When sailing, Hopkins simply hits the log button and starts recording data. After racing, he transfers the data from the logger to his laptop via a memory stick and views the results in the Toolbox. In a few hours, he’ll have a report out to the team. The video is synced with the data, so, if need be, they can watch a specific maneuver alongside the boat’s vital signs, such as wind angle, boatspeed, acceleration, rudder angle, and pitch.

One of the frustrating things for navigators is analyzing straight-line performance using traditional strip charts. “They end up with a huge log and can’t fnd the part that they want to know more about,” says Hopkins. “If the log includes the period between races where the guys are having a sandwich, or when another boat is camping on you, it doesn’t work.”


Instead, the Pi system allows him to define what he calls “performance mode.” The logger instantly records when the boat is within a specifed number of degrees of its target angle and knots of its target speed.

“When certain conditions are met the data is deemed to be good,” he says. “If I watch a trace around the course I can see when the boat was sailing unimpeded and when it wasn’t.”

Hopkins also developed a way to watch all maneuvers, such as tacks, laid across each other. This allows him to see how many meters were lost in each tack, plotted against variables, such as turn rate in degrees-per-second or speed going into the tack.


And yet another critical application is a far better understanding of the boat’s sail inventory. The same level of data and analysis can be done on each sail, allowing them to more effectively compare the crossovers from one sail to another.

“In the Block Island Race, we were reaching and tried three different sails that we thought we knew well,” he says, “but using the analysis, we found not just which sail was best in each condition but the difference between the best and the second best sail. From that, and being able to put a value on every maneuver, a sail change for example, we realized that those differences are really important to understand when you’re making the decision to change to another sail.”

While Hopkins, and other top end programs—Niklas Zennström’s Rán, the Groupama trimaran, and assorted America’s Cup and Volvo Ocean Race teams—continue to independently develop the system to suit their needs, Cosworth has introduced a model developed for dinghies and keelboats alike.


The Garda system, which uses a smaller data logger (2″ x 3″) with integrated accelerometer and GPS, accepts up to six different sensor feeds. It’s been in development with the British Olympic Sailing Team since 2004 and has found its way onto foiling Moths, sportboats, and of late, says Cosworth’s Alex Reid, it’s being use by more and more keen weekend racers. A new partnership with Tacktick electronics (it can interface with the Tacktick system) has accelerated its use amongst serious amateur teams.

International Moth champion and pro sailor Adam May has been using the system as well and says it has opened up a new realm of things to study.

“You have to want to do it,” he says, “but once you do, it leads you off into all sorts of places. That said, you have to go into it knowing what you want out of it.”

Through his experience with the system, May eventually learned that he was losing less distance when jibing than he thought, and this discovery has since influenced his tactics. He’s much more inclined to jibe for tactical reasons.

The Garda system starts at $2,823, which includes the hardware and Toolbox. From there, the user can add sensors as they see fit: tiny load cell pins, laser sensors, etc. “It’s a very flexible system,” says Reid. “You can do virtually anything.”

While most sailors don’t have the time nor technical prowess to develop elaborate analysis formulas to the extent that Hopkins and others do, Reid says they are continually refining the Toolbox software to make it more plug-and-play and userfriendly.

“At Robert’s level, they can develop all sorts of tools,” says Reid. “But for the weekend guys, we have templates to load into, and they can go from there.” At the end of the day, he adds, the system is only as good as the answers one gets by asking it the right questions, and how quickly the answers are delivered to the sailors.

“We’ve been using it to think of ways to go faster,” says Hopkins, who adds that Bella’s owner, Fauth, has benefited from the in-depth analysis of his helming technique.

“The boat is a solid six lengths faster around the same-length course than it was a year ago. And, as a sailor, it’s inspired me to question everything I feel is intuitive. I can ask the most complicated chain of questions to capture that seat of the pants thing. We never had that kind of agility with any other software.”


More Gear