Downloads of the
SailTimer tacking app have increased 5-fold during covid-19. To all of the new users around the world: welcome! You now have the most advanced sailboat navigation system, right on your phone/tablet. Whether you are cruising, racing or just going where the wind takes you.
The SailTimer navigation system is deceptively easy to use. On boats of any age and size, it gives you functions that were previously only available to professional tacticians -- and some capabilities that never existed before. Start by choosing a waypoint or route. If you have the wireless
Wind Instrument RB™, your optimal tacks update automatically as the wind or your location change. If you are using the app for chartplotting but don't have the Wind Instrument, you can manually enter the wind speed and direction to plan your tacking route. As noted in a previous issue,
Navionics charts work great in the SailTimer app on Android and iOS.
SAILBOAT NAVIGATION IS EVOLVING
VMG (Velocity Made Good) is being phased out. The concept was helpful 50 years ago when there were no PCs, smartphones or GPS. But a major section on the VMG
Wikipedia page is about confusion in the definition, especially in "an ordinary GPS unit". Even now, if you buy an expensive GPS chartplotter it determines
laylines using the old method of VMG into the wind from before PCs and GPS existed.
In the age of GPS, smartphones and navigation apps, there is no reason to measure your progress based on velocity into the wind. Kind of like buying an expensive marine radio that communicates with smoke signals. Obsolete. Can you imagine if Google Maps assessed traffic routes based on speed into the wind? Totally unnecessary. VMG problems are explained further at
NauticEd. Measuring tacking distances is easy with modern GPS locations, but the SailTimer app is the only product that uses tacking distances to calculate your optimal tacks. The website for the SailTimer app also has more detail on how we pioneered the modern method of
polar plot learning (storing your boat's custom speed profile on all points of sail), with an accurate calculation method that replaces polar "targets" from 50 years ago. For navigation using electronics, VMG and polar targets are on the wrong side of history. If you know of any published example using them from around 1970 or earlier, we would be interested to receive an
email about it.
GOING WHERE THE WIND TAKES YOU
Whether in a keelboat or a sailing dinghy, sometimes it is nice to just go where the wind takes you. You may be coming back to the same dock later, so you may not bother entering waypoints or planning a tacking route. But if you end up downwind, you may then become very interested in minimizing the number of tacks to get home. Later you may also want to look at the
GPS track of your tacking, or show someone where you went. And when a big gust hits, you may be interested to know exactly what that wind speed was, and how fast you went then. So even when used casually, there are lots of benefits to this new technology.
