Seven GPS Navigation Tips for Safer Cruising

Here’s another great cruising tip from our friend Captain John at!

Tap into the hidden power of your nautical GPS. Set your GPS alarm functions to warn you when you approach dangers or cross over significant boundaries. Put these seven alarm tips into play today to keep your small cruising or racing sailboat safer than ever before.

1. Approach a Waypoint.

Most GPS receivers beep when you get within half a nautical mile or so of a pre-determined waypoint. Pull up the “proximity” menu. This allows you to select any waypoint, increase the distance of the alarm, and toggle the alarm. Your proximity alarm has a distinct series of beeps to distinguish it from other alarms.

2. Turn Onto a New Course.

Do you have a critical turn up ahead? Will it require heading up, falling off, tacking, or jibing? Set the alarm to trigger well ahead of time. Now you can prepare to trim your sails for the new course. And, you’ll have extra time to take over the steering from the auto-pilot or wind-vane.

3. Make a “Bulls-eye Landfall.

Few things are as important as sighting an island peak or blinking light after days at sea. But few things cause more apprehension. You need time to orient yourself, double check that you are where you want to be.

Move the distance of your alarm so that it sounds when you are at least one hour away. This allows you time to scan the horizon with binoculars, get the anchor ground tackle ready, and make preparations for chart navigation in coastal waters.

4. Sail Onto Soundings.

When will you cross the 100 fathom curve? For centuries, this has marked the nautical boundary between offshore waters and coastal waters. Even if your depth sounder won’t sound that deep, check the navigation chart and set a waypoint at the spot to trigger an alarm.

5. Cross Over a Contour Curve.

Squiggly lines or enclosed circles on the chart show a number somewhere in the break of the line or circle. Check the navigational chart to see whether this denotes fathoms, feet, or meters. Program the alarm to sound when you cross specific contour curves as a backup to your electronic navigation.

6. Pass Close to a Danger.

Determine the closest safe distance to pass rocks, reefs, mud flats, or sand bars. Use your nautical chart to determine the latitude and longitude of the danger’s center. Program this as a waypoint.

Use your nautical chart to draw an enclosed circle around the danger. Increase the radius by 50%. Set the radius for that waypoint in your GPS proximity function.

7. Warn of a Dragging Anchor.

Draw a swing and drag circle around your anchored position. Set your alarm to trigger when the boat touches the edge of the circle. Make sure that you allow enough room for your small cruising boat to swing with wind and current changes.

Captain John’s Sailing Safety Tip
Use updated nautical charts to backup and verify your GPS or electronic chart display.
Lose power or signal reliability and traditional navigation techniques will get you home.


Use these seven sailing tips to make your sailing navigation easier and more efficient. Combine the tradition of chart navigation with the high tech of the nautical GPS for a powerhouse system of safety that’s hard to beat!

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