Ok, letting the geek out for a moment… how cool is sailing in the digital age? I mean, I know that people have sailed for ages and I admire Polynesians who sailed by stars, currents and winds. And those who used sextants. Or even fifteen years ago when we learned how to determine boat position based on sightings and how to plan your route waypoints and calculate the offset from current.
In comes technology. We drive Rainbow Safari like a car with GPS. The 12 inch touch display at the helm gives hours of digital entertainment (aka touch-and-try to figure out how it works).
We just finished our first night crossing on the way from Phuket to Sabang, so here is a quick look at the instruments:
Sorry if the “night view” photo is blurry, it was taken in low early morning light in slight waves. From left to right: Our bearing is 245 degrees (Southwest), wind is negligible at about 4 knots from the North. The autopilot is steering us to the waypoint in Sabang, which at current speed we will reach in 1 day and some hours. It is automatically adjusting for drift and current. There are no obstacles or other ships on the radar, except for our buddy boat SV Field Trip on starboard. At night we had a small thunderstorm off to port, and the radar showed us cloud and rain and made it easy to track and avoid the weather.
Field Trip is also visible on the screen through AIS (automated ship identification), a VHF-based transponder that gives us course, distance, and speed of our buddy boat. And any other ships near by, like the large cargo ship MCC Medan that crossed our path at night: 0.67 nautical miles away at the nearest point. We had all his information on our chart plotter (screen), he would automatically see us on his chart plotter with our boat information, significantly reducing any risk of collision.
During our second night out at sea we crossed the traffic that come out of the Melakka strait, passes North of Sumatra and heads towards the Indian Ocean and eventually the Suez canal. This is part of the busiest shipping route in the world, bringing Chinese goods to consumers in Europe, and a lot of gas and oil from the Middle East to Asia.
Over the course of 4 hours we probably crossed paths with 20-30 big ships, with close to ten crossing within 2 nautical miles of us. You really don’t want to be any closer when they move at speed and it is dark around. All you see are some navigation lights and you need to try and derive their angle to your course and speed and whether they are on a collision path. Again AIS is brilliant, as it calculates the nearest distance they will be, and the time until they will be at that point. When one ship appeared in range the AIS showed a nearest distance of 200 feet in about 45 minutes… much too close for comfort, so we changed speed and direction to increase that distance.
One of the ships did not have a functioning AIS and only showed as a blip on radar, reminding us not to just rely on one system, but to use all our senses and sensors to stay safe.
Speaking of weather, of course I checked the Windy app before we left and looked at the wind forecasts for our crossing. Based on global wind models it gives me an animated wind map for the next days. We don’t have satellite communications (yet), but early morning Field Trip downloaded updated weather info via their Iridium satellite receiver and gave us the update via VHF. (In the traditional way: “wind is supposed to pick up in 3-4 hours to 10 knots so hopefully we can switch off the engines!”)
Windy is also super useful for tide and wave information, so whenever we anchor in a new location we can easily see how the depth will change with tides.
End of a very quick excursion into modern day recreational boat navigation. Kind of cool (when it works :-))
Rainbow Safari 