A column by Margaret Pommert
Onboard Fifteen year old, Advik Eswaran has developed a free boating app for route planning in Washington State’s San Juan Islands.
Free Tidal Current App from Local 15-Year-Old How long does it take to travel by boat from Anacortes to Friday Harbor? Many newer boaters trust navigation apps, like Navionics, to answer the question. But even when they adjust app settings for their planned boat speed through the water, the answer is often very wrong here on the Salish Sea. Why? Tidal currents. As the tide ebbs and flows, the currents in and around the islands can be moving as fast as 3 or 4+ knots. Depending on your heading and the direction of the current, the current may be pushing you or slowing you. Experienced NW cruisers and racers know to plan their route around tidal currents. How? As a navigation instructor, I teach my students to use tidal current tables and charts to estimate the impact of current on the speed to their destination. This is called “speed over ground,” which can be very different from “speed through the water,” which is what a knot meter reads. Developing these estimates is time consuming, especially for a route that may take several hours. Worse, the estimates depend on WHERE you are and WHEN. If you decide to depart at a different time or change your boat speed through the water, you have to re-estimate. Good news! Thanks to the design prowess of 15-year old developer Advik Eswaran, there is a new free IOS app called SoundRouter that does these calculations for you! SoundRouter is a simple and intuitive marine routing app based on tidal currents that lets you choose from popular departure points and destinations around the San Juan Islands and surrounding waters. Once a departure point is chosen, the app will present a list of alternative departure times during the selected days and the associated estimated time en route (ETE) for each option.
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“In simple terms,” Advik explained, “the math used here is basically just time equals distance and velocity, meaning the time it takes to sail a certain route is the distance of that route divided by the boat speed plus or minus the speed of the current. I also used a version of a complicated algorithm called Dijkstra’s algorithm.” Advik knows the local waters well, where he has competed for four years in the Northwest Youth Racing Circuit racing Optis, FJs, and Lasers. He also has gained a great deal of experience while cruising with his family on their C&C 25. “What inspired me to create the app was the work involved in trying to optimize a certain sailing route for the currents along the way,” he said. “My family also had a boat in Oak Harbor, and when we wanted to go to the San Juan Islands, we needed to travel through Deception Pass or Swinomish Channel, where there are really strong currents. Once I was trying to figure out what the best time would be to go through Deception Pass, and I kept thinking, isn’t there an easier way to do this?” Well, now thanks to Advik Eswaran and his creation of the SoundRouter app, there is! For more information or to provide feedback, visit www.mymariner.com/. Bravo Zulu Advik! Onward! Seattle-based Margaret Pommert is a licensed 100-ton captain, certified sail, power and navigation instructor, leader in the woman boater community, safety at sea advocate.
