SailTimer; the app, the GPS, & the Wind Vane
It’s time to catch up on Dr. Craig Summers and his passion for Tacking Time to Destination (TTD). The basic idea is to calculate in advance how long it will take to tack (or jibe) a sailboat to point B in particular wind conditions, but there’s a lot to it. Like how does the software program or dedicated device know exactly what your particular boat can do those conditions — a set of performance values known as polars — as well as what the boat and wind are doing in real time so it can perfect its predictions? And what about currents? When we last discussed SailTimer in 2009, Summers had introduced a rudimentary iPhone app and was working on something called The Sailing GPS. The latter is real now, the app is several generations advanced, and that’s not all!
If you have an iPhone or iPad the easiest way to get a feel for Summers’ work is to install the free SailTimer Charts Edition app. That’s all I used to get the screen shot above, which suggests how long it would take an average 37-foot boat with 14 knots of ESE wind nearly on the nose to sail from my home to a waypoint I dropped off Nova Scotia. Sometimes the waypoint management seems a little twitchy but beyond that all I had to do was Input boat size and estimated wind speed/direction. Once the Optimal Route was (near instantly) calculated I could use the arrow tool seen lower left to flip first tacks and I could also tap on the route line to get that boxed detail on the individual legs. It’s only an approximation to be sure — and I would probably wait for a wind change anyway 😉 — but SailTimer has much more going on…
Click the screen above bigger and check out the Options Menu at the right. From within SailTimer you can not only purchase various chart packs but also a $10 module that let’s you use polars specific to your boat. You can also display your sailing route over satellite photos even in the free app and/or buy a $5 module that will overlay ActiveCaptain information. Now look to the left at the Input Set Up menu. It’s no surprise that you can use GPS (the Bad Elf Pro Bluetooth model works great) to track your vessel and display/collect SOG/COG data, but how about a SailTimer Wind Vane system that not only connects wirelessly to your iThing but also reports its battery state to the app?…
Yup, the $689 SailTimer Wind Vane is a solar-powered sensor that can purportedly reach as far as 300 cable-free feet to its little blue battery-powered base station, where the data is turned into NMEA 0183 formatted Wind messages and sent out again over WiFi. There’s also a Bluetooth version that can be used with certain phones that don’t have WiFi as well as with The Sailing GPS ($399) seen on my truck seat below. I didn’t get to go sailing with the test unit, but it did seem capable of doing the same TTD calculations as the SailTimer app. And I haven’t mentioned yet that either can be used to build custom polar tables if wind data is available.
Probably the best place to dig deeper into Craig Summers’ world of TTD predictions is at the SailTimer app site but also note that I passed the loaner Sailing GPS over to Dan Corcoran, who not only did some realistic testing with it last summer but also tried the wireless wind vane and the app. Apparently Dan wasn’t very impressed, but then again he’s often quick to see what’s not in a product and he takes his instrumentation very seriously. Which, incidentally, may have something to do with why he and his crew were recently awarded the Allegra Knapp Mertz Memorial Trophy for overall racing performance of a non-spinnaker sailing yacht with a PHRF handicap of 139 or higher across the 63 member yacht clubs in the Yacht Racing Association of Long Island Sound. Big congratulations to Dan and I’m sure we’ll hear his views on the current SailTimer product line in the comments section…
Heck, maybe Dan will write an entry about some of the other apps that attempt to do TTD style calculations and where he’d like to see the technology go. And Dr. Summers certainly isn’t done yet. For instance, I was pleased to hear that he’s working with companies like Digital Yacht and DMK who are developing hardware that can put a boat’s NMEA 0183 or 2000 wind, GPS, depth, etc. onto WiFi, as shown in that beta SailTimer “Onboard Network” menu at right.
That means means a sailor will be able to get the full benefit of SailTimer without the specialized hardware, and that the same sailor can try other apps that may try to accomplish similar goals.
But they might run into SailTimer elsewhere, too. For years now, Summers has licensed his algorithms for use in programs like MacENC and Fugawi (I’m about to test the all new Fugawi 5 edition) and that also happened recently with RudderNut’s Tack Pad app. If you already have an iThing, Tack Pad is also free and it’s a neat example of a very different approach to the complex calculations that SailTimer does. For instance, those values at bottom left below change as you finger drag an orange waypoint around and you can also set wind speed and direction for each waypoint with your finger. I’m not entirely comfortable with the fact that Dr. Summers has claimed trademark on TTD — it seems like an obvious term and acronym to me — and has also patented algorithms that may be obvious to some programmers, but I certainly admire his persistence about making the world more aware of Tacking Time to Destination.
SailTimer, gone iPhone & handheld
November 16, 2009
Tacktick Micronet, part 2
August 29, 2007
GPS Visualizer, A Nice Ship’s Log Tool
September 19, 2004
SeaNav app, now with AR, GoFree, and Pebble!
December 17, 2013