Don't Lose the Plot  –  The chart plotter is one of the most under-utilised tools the skipper has at his/her disposal. Not only will it show you where you are, if properly calibrated, but it can show where you have been, where you are going to, and most important, where you are relative to a known position. This last aspect is very useful when you are attempting to carry your plotter data onto a paper chart (which every decent navigator does as a matter of course, right?).

First, set up a position at a point on the chart—many sailors use the centre of a compass rose on the chart. Transfer this position to the plotter by calculating the latitude/longitude data on the chart. Then set up a GPS waypoint on the electronic chart to correspond with the centre of the compass rose. This way, when underway, you can take a quick read off the electronic chart, which might indicate that you are, say, 3.5 miles away from your waypoint, at a bearing of 180 degrees (true or magnetic, you get to choose). It's not hard to draw this off on your paper chart and thereby record an electronic fix every hour or so.

It's essential when taking a charter yacht to purge the electronic chart plotter of all waypoints, routes and go-tos that might be entered by other sailors. This way you won't be confused later. Many sailors don't bother to name their waypoints, so they are entered as WP1, WP2, etc.—which is no use unless you fully know what they mean. Equally, an entry such as “Anegada” tells you nothing unless you know where in Anegada the waypoint was set. You don't want to follow a heading to such a waypoint thinking it'll take you to the Channel entrance outside of Setting Point when it really denotes the second mooring ball in the first row off the Anegada Reef Hotel.

Another useful attribute of the electronic chart plotter is its ability to help settle issues of International Law. See the accompanying photo showing the screen for Guantanamo Bay. The chart clearly reads “Cuban Territory Illegally Occupied by the USA.”  This information has helped me settle a few arguments and, once, won me a free dinner. It should be worth a drink or two on your boat if you can properly foment the discussion.