Electronic Navigation
We are well into the 21st century. Chances are that within 30 feet (10 meters) of you right now there are 2-3 GPS-enabled potentially lifesaving devices: your iPhones and iPads, Android phones and tablets, and perhaps even your watch. Given that these are so accessible, it would be irresponsible for even a rudimentary introductory boating course to not include the basics of using these devices to get you home or navigate out of a bad situation.
With these mobile devices, you can download navigation apps that will accurately show your position on a chart and give you lots of other essential data.
It seems like we all end up in the British Virgin Islands sometime so we are going to work with the Navionics App.
Below is an animation of the lay of the land of the BVI. Tap on an island to zoom in then tap on the home button to zoom out.
Next, here is an animation using the iPad. Start by tapping the Play button then continue following the instructions or hit the CONT. button.
You will first measure the distance from the Road Town outer navigation markers to The Indians (one of the best places in the BVI to go snorkeling; it is often the first stop for charterers visiting the BVI).
Then you will start the navigation and you will see a data window pop up which shows Speed, Track, and Distance. The Skipper will exit from Road Town and then turn onto the correct track to sail directly in a straight line to the Indians.
The great thing about this is that it shows your track in a red line ahead of you. This is your real projected Course Over Ground (COG). It is not your heading because the mobile device has no way of knowing which way your boat is pointing, but it does know based on previous GPS positions where it has been and so projects a track out in front. So wherever you need to go, you just turn the boat until the mobile device projected track lands on your destination then take a note of your heading and lock that in. This is your real direction of movement of the boat no matter what the current or leeway. Kinda feels like it is cheating. But it’s not. Note, however, that the currents and leeway change so you need to check often to make sure the red line is still landing over your destination. You also need to be very aware that your projected track is safe with no reefs, rocks, islands, or continents in the way.
There is a lot more to know about electronic navigation. This is just enough for now to get you home.
In fact, there is so much to learn and grasp that NauticEd has an entire course on Electronic Navigation.
