you won’t get any closer to the windward mark and your VMG will be zero. On the other hand, if you point
straight upwind you won’t go anywhere, so your VMG will again be zero. Somewhere in between head-to-wind
and a beam reach lies a “magic angle” that will optimize your upwind speed and make you a champ.
Unfortunately, this elusive angle depends heavily on your gear, the prevailing conditions, your size and your sailing
style.
The S5 takes GPS speed readings every second to get your actual speed. The device then uses trigonometry to
extract the component of your actual speed that is aligned with the upwind-downwind line defined by the mark
locations you entered (this line corresponds to the line that the imaginary powerboat traveled along in our example).
This process is repeated every second and the results are displayed on the oversized LCD screen.
This steady stream of easy to understand (big number = good) feedback allows you to precisely dial-in on the magic
angle for your current setup. It also provides priceless insight into which gear combinations and settings work the
best for you in a given set of conditions.
How accurate is the S5?
In speedometer mode the accuracy of the S5 is better than +/- 0.2 knots (0.36 km/h). In VMG mode accuracy of the
S5 depends on what angle to the wind you are sailing but is generally better than +/- 1 knot.
How long do the batteries last?
Regular alkaline AAA batteries will last longer than 20 hours. There is however a small drain on the batteries
when the device is turned off. This is because battery power is used to keep the GPS memory backed-up. This
memory allows the device to re-initialize and find a GPS solution quickly when it is turned on again. If you intend
to leave the device switched off for more than a week, removing any one of the three batteries from the battery
holder will stop the batteries from being depleted in storage.
What is the black phone jack on the circuit board for?
This jack is used for programming the speedometer in the factory. It cannot be use to download data from the
device. Please do not connect anything here.
www.velocitekspeed.com
