What would you do next? Tech failure onboard
a) Send a DSC alert (digital selective calling) from your ship's radio followed by a Pan Pan voice call on Channel 16?
b) Turn directly towards the shore and drive until land becomes visible?
c) Fix your position using an alternative means?
Adrian Bannister, RNLI Lifeboat Trainer
Fix your position using an alternative means (C). You can check your proximity to any navigational hazards on the chart, like shipping lanes, wind farms and shallow waters. You can then decide if you continue, turn around, or head to the nearest port.
The method of fixing your position might differ depending on whether it’s day or night.
Ideally, you’d always carry a portable GPS or GPS-enabled mobile device.
If you have one, use that first.
If not, and it’s daytime, use your ship’s log, or previous fixes on your chart, to work out your last-known position. From that, apply dead reckoning, factoring in tides and tide streams, plus nearby physical features like buoys, to estimate your current location.
At night, without a backup GPS, yachtmasters can also use rising and dipping distances in conjunction with an Almanac, to calculate the boat’s distance from a light on the horizon.
Every vessel should have a chart onboard for the appropriate area.
Pack plotting equipment including a Portland plotter, parallel rule, or a rib plot, plus something to measure distance, like a pair of dividers. And a 2b pencil (plus sharpener).
Always navigate with extreme caution. Even when boating out of sight of land there can still be the risk of grounding, so ensure you have sufficient depth of water by checking charted depths and watching the echo sounder.