Sail Fast with SailBot
Start Better. Sail Faster.
The SailBot Sailing Instrument is a simple application that turns your phone into a powerful sailing instrument for sailboat racing. SailBot provides a cost effective alternative to buying expensive dedicated sailing instruments.
SailBot displays distance-to-line and an adjustable start timer during your pre-start preparations and start sequence. When the start timer runs out and the race starts, SailBot automatically switches to display speed, heading, and VMG to the wind.
Distance to Line & Start Timer
Speed | Heading | VMG
Instructions
The starting view displays a distance to line calculation on the top and an adjustable timer on the bottom. When the timer completes, the view will be switched to the racing view. Switching between views manually can be done by pressing the "Switch View" button on the bottom left of the screen.
Start/Pre-Start View
Once the race committee has set the starting line, sail by each end of the line and "ping" each location. To ping the starboard end of the line, press the green "Boat" button. To ping the port end of the line, press the red "Pin" button.
SailBot will now display (while in starting view) your distance to an infinite line extending through both ends of the line.
Because the distance calculation is based on an extension of an infinite line extending through both locations, you do not need to sail right up to the boat or pin to ping either side.
You can simply ping the line from an extension of the line by lining up the flag on the committee boat with mark on the other end of the line and touching the boat or pin button (depending on which side you are on) at that time. This allows you to ping the line while staying out of the way of other fleets’ starting sequences.
Racing View
The racing view displays speed and velocity made good (VMG) to the wind side by side on the top and course over ground on the bottom. The racing view will also show only speed or only VMG on the top by "long pressing" either the current speed or current VMG readout respectively.
The application saves the most recent racing view configuration that was enabled, and can be returned to the previous state by "long pressing" the single speed or VMG readout a second time.
To set the wind angle for the VMG calculation, press the "Set Wind Angle" button on the bottom right of the screen. This will pop up a number picker in the center of the screen for manually setting the wind direction.
Hide this number picker by pressing the same button that now reads "Hide Wind Angle."
Please note that the VMG readout is an absolute value of the VMG and will therefore read positive both upwind and downwind.
Gear Recommendations
Supplementary items can make this application even better
Bluetooth GPS Recommendations
I use the Qstarz 818XT Bluetooth GPS Receiver, but there are other solutions as well like the Dual XGPS150A and the GlobalSat BT-368i. I am recommending the Qstarz 818XT because I use it and know it works great, but if you do a search for Bluetooth GPS Receiver on Amazon you will find many options and plenty of reviews of products if you do not want to go with my recommendation. One thing to keep in mind is the update frequency as discussed below. You will probably want something that has a 5 Hz update frequency (5 times a second) .
To connect your phone to the Bluetooth GPS download the free app called "Bluetooth GPS" from the google play store.
The Pelican 1010 micro case or the OtterBox 1000 Series Waterproof Case are both good options for protecting your GPS from the elements.
There are several good reasons to use a Bluetooth GPS receiver with this application:-
Battery Life
The internal GPS chip in cell phones require a lot of battery to operate. When using the internal GPS with my phone and the brightness set at full, I experience around 3 hours of battery life. By using the Bluetooth GPS receiver, I am able to get approximately 5 1/2 of continuous use with the screen brightness on full.
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GPS Update Frequency
Though battery life is very important, another huge advantage to "outsourcing" the GPS function of the phone via a Bluetooth GPS Receiver is the increase in update frequency. The typical phone GPS chip updates its location at best once every second (1 Hz). With a Bluetooth GPS, this update freqency can be as high as 10 times a second (10 Hz). The Qstarz 818XT has the capability to update at rates up to 10 Hz via a hardware switch. This switch can be programmed via a usb cable and a computer program comes with the unit. I have been very satisfied by setting this update rate to 5 Hz.
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GPS Accuracy
The accuracy of the chip in a Bluetooth GPS will be much better than the GPS chip that is built in to modern day phones.
Waterproof Case Mounting Solutions
Bike Mount + Velcro
I use a bike mount waterproof case (like the one on the left) for my Samsung Galaxy SIII. I bought mine on ebay for $25, but similar ones are also available via Amazon. I attach this to the boat via 3M Dual Lock "Velcro". Other inexpensive waterproof cases are also available such as ones from iPEGA as well as the waterproof bag type cases. More expensive premium cases like the SEIDIO OBEX case are also available for the Galaxy S3, and I am sure there are similar solutions for other Android phones as well.
In my experience and due to the waterproof cases having a plastic screen protector over the screen, glare is significantly reduced compared with the straight glass screen of the phone.
3M Dual Lock Fasteners
3M Dual Lock is a great product. It provides a superior reusable mounting solution to traditional Velcro. This product is meant for high temperature environments and does not wear out as quickly as traditional Velcro. I personally have tested and use the Dual Lock 250 on both my phone case and boat (the number signifies how many fasteners per square inch and thus is representative of how strong a connection you will get). They also make this product with lower (170) and higher density (400) of fasteners, but the 250 to 250 connection is very strong and is what I recommend. This product is available via Amazon for $20-30 for two 10ft rolls, or email me and I can send you a couple feet via USPS for a small "donation".
Contact
Need help setting up the app?
Have any requests for new features?
For any questions or suggestions, please contact SailBot @ sailingdroid@gmail.com