Dial Up Your Performance With An iPhone

Philippe Kahn isn't just calling friends with his iPhone: he's calling laylines too. An electronics review from our November/December 2010 issue

February 2, 2010

Courtesy of FullPower| |Laying tracks across a big, blue sea: Pegasus 50‘s record-breaking run in the 2009 Transpac is recorded on the author’s iPhone.| It wasn’t long ago when we’d get on our boats and stash our phones somewhere nice and dry, pulling them out occasionally-if ever-to check in with the home, office, or nearby airport for real-time wind reports. Some of you might’ve even left your phone or PDA in the car because it was of no use on the boat. Not anymore. We now carry our phones with us everywhere-for me, it’s an iPhone 3GS, which is a powerful phone and an invaluable sailing tool. With a built-in GPS, magnetic compass, and accelerometer, as well as a highly readable multi-touch screen, thousands of applications, and accessories that include waterproof cases and solar chargers, the iPhone is a complete solution for sailors. It is now my navigation station and much, much more.

The iPhone 3GS is the only phone in existence that gives you an accurate compass when operating in a fully connected environment. We all know how important headings are when sailing, and particularly when racing. Using the iPhone as a navigational tool, I also no longer need to worry about finding or sharing my geographic positions.

For charting, there are excellent, inexpensive offerings, such as Navionics and iNavX, which allow you to download and use the same navigational charts that you would use with a much more expensive, fixed chartplotter. There are also numerous tide applications such as Aye Tides. For wind information, iWindsurf and its free Wind Alert application are hard to beat-it’s all there on your phone, so you need not go searching for it.
In the interest of full disclosure, my company, fullpower, built a navigational application called MotionX-GPS Sport for my own use, so naturally, this is the one application I use for all my navigation these days. This is not to be confused with MotionX-GPS Drive, our other iPhone application, which will guide you turn-by-turn to the yacht club to change into your gear, but no farther.
Literally hundreds of applications are developed for the iPhone every day, and even as you read this, I may be using some of them in addition to MotionX, but for now, let me share with you what I’m really using my iPhone for. It’s always with me and I’m always connected worldwide, so these applications apply in San Francisco, Honolulu, Porto Cervo, Key West, or La Rochelle.


The MotionX function we (Team Pegasus) use most often is the track recorder, which keeps records of all of our sailing. On the way in from the races or a practice session, I automatically share the day’s tracks and waypoints with the entire team so they can review them later onshore.

It’s amazing what we learn from our tracks. We can see the shifts that we missed, and, if we’re doing a two-boat practice and both teams are recording their tracks, we can better understand and review what happened and when. By analyzing the GPX file (GPS Exchange Format, which is a data format used for the interchange of GPS data -waypoints, routes, and tracks-between applications and web services on the Internet), we can check for boatspeed differences and persistent geographic shifts. By collecting this same data as we sail a similar course on different days, we can accumulate know-how on local knowledge, have it all in our logbook to review at the debrief, or at the end of the season.

I always store the coordinates of fixed racing marks in each of my regular sailing venues into my MotionX logbook. I have hundreds of waypoints named and sorted, and I even attach pictures to my favorite waypoints. I also store my tracks from all previous sailing venues for future reference, and I can annotate notable tracks with local knowledge information. For example, when we get to Key West Race Week, we won’t have to guess where we need to go to practice. We’ll simply follow our track to the previous year’s racing area and practice by following the winning racetracks, which allows us to immediately focus on what matters in Key West-building on the previous year’s experience.


For any practice session, we like to set marks by range and bearing instantly. Using the navigation screen we are able to take the guessing out of practicing. For example, if we want to set the top mark at 0.75 miles and a bearing of 225 degrees true, we set it as a waypoint and sail to it. Once there, we can drop the mark and start practicing. Yes, you can do this with a handheld GPS, but the touch screen technology of the iPhone makes entering marks far easier than with any handheld I’ve ever used. You can enter waypoints instantly and these waypoints can be shared instantly with another iPhone, your training partner for example, and made part of your logbook. You can’t do that with a pair of handheld GPS units because they’re not connected.

Because we sail a lot in San Francisco, we rely heavily on monitoring our velocity made good in order to understand what the current is “really” doing; tide prediction tables can often be slightly off. For this, the MotionX-GPS Sport’s compass page has a live compass and displays all the fields we need to get VMG: Speed Over Ground, Course Over Ground, Heading, and VMG are all right there. It takes a lot of work to get all of this to display on a typical processor-and-mast-mounted display system. We use this page whenever there’s current or when we’re wondering whether we are better off sailing faster and lower or higher and slower and finding the mode with the best VMG. When sailing in current, people’s instinct is many times wrong. You can’t argue with the numbers.

Courtesy of FullPower| |**The author’s company, fullpower, developed he MotionX-GPS SPort application, with racing in mind. The compass page (left) has all the functionality of a high-end electronics package. The tracks page (middle) allows the user to access and manage tracks and data from past races and practices, and the map page integrates waypoints, tracks, and notes. **|


Taking it offshore
While we’ve developed plenty of uses for our iPhone for racing around the buoys, the applications for offshore racing are equally compelling. As navigators and offshore sailors, our basic needs are to find our geographic position and show it on a chart, record and store our track for future use, measure our performance or speed-of-advance to our destination, follow someone else’s track to gain local knowledge, store and share all this information, and have a simple safety system that can instantly pinpoint and share our position in case we require help or even rescue. We also want to keep our friends on shore up to date with what is happening on board by way of text messages, images, and videos, all of which can be gathered with ease by the iPhone.

The MotionX-GPS Sport application can share directly on Facebook, Twitter, and over e-mail. So when you’re racing offshore you can create an automatic Facebook blog that Tweets every time you make an entry.
Geo-tagged pictures attached to your positions and tracks are automatically attached. This is how I built my log from the 2009 Transpac Race (, sending video clips, images, and updates.

But we weren’t just using our iPhone to keep our friends entertained as we tore across the Pacific at record pace. Mark Christensen and I (we sailed the doublehanded division) each had an iPhone 3GS, and for the entire race, using MotionX-GPS Sport, constantly shared performance data waypoints, and optimized our VMG using the very same pages we would sailing on San Francisco Bay.


When racing doublehanded, though, we don’t see each other much. As a result, we even found ourselves using our iPhones to analyze and share information when one of us was in the bunk and the other on deck. We were on the same boat, but we sent text messages to each other and exchanged ideas on a wide range of items, including, for example, whether to accept a slightly less favorable and temporary VMG to get further south and look for more wind. I never had to leave the helm. We had 12-hour watch rotation (he took the days and I the nights), so at each rotation we agreed on a new waypoint that we shared between our phones and then optimized VMG to that waypoint and kept tabs on each other-all from the palm of our hands. Using the MotionX-GPS application, we could simultaneously look at the shared information on each of our iPhones. The ability to constantly monitor VMG for more than seven days and easily exchange information made for a great outcome, not to mention we were remarkably rested upon arrival in Honolulu.


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