Please select your home edition
Edition
Kiwi Yachting - Lewmar

Using simple danger bearings for sailing navigation safety

by John Jamieson on 31 Dec 2011
the treacherous Wide Bay Bar - shallow, with breaking surf on one side and rocks on the other .. .

Strong winds heel your cruising boat as you approach the rock-infested entrance to the pristine cove you’ve selected for an anchorage. Your main concerns are those ship-killing rocks on the starboard side of the entrance. What‘s the fastest, easiest method to back up your GPS navigation for safe passage?

It's easy to ignore traditional forms of navigation with so many touch-pad black box navigation devices at your fingertips. Shorthanded sailors in particular need fast, easy, works-every-time methods that require a minimum of chart work.

Use the simple danger. All your chart work can be done dozens of miles before you get close to shoals or dangerous reefs. It's fast, fun, easy, and accurate. Grab your trusty hand bearing compass and follow these easy steps:

1. Choose a Prominent Object:



Study your navigation chart and find a prominent object on the same side as the danger.

For example, if an outcrop of dangerous rocks lies to starboard, select a prominent tank, tower, lighthouse or other object on the far side of the danger on the starboard side. Note in the illustration that the dangerous reef lies to starboard. The sailing skipper chooses a prominent Tank (note: on nautical charts--prominent, easy-to-see objects are always labeled in all capitals) on the far side of the dangerous reef on the same side as the danger (to starboard).

2. Plot the Danger Bearing Line:

Draw a line from the charted object back out onto the water (see illustration) on the outer edge of the danger. Note in the illustration how the line clears the danger. Extend the line far enough so that you can start taking bearings one to two miles before you pass the danger.

3. Measure the Danger Bearing Line:

Find the magnetic bearing of your prominent object. This will be the danger bearing you'll use. Check your measurement three times for safety's sake. That might seem silly, but parallel rules, protractors, and other measuring tools can slip and slide. Your bearings should read the same.

4. Label the Top of the Danger Bearing Line:

Label lines for safety. Not many things are as important as crystal clear labels in navigation, in particular with short-handed crews in tough sailing conditions. Danger bearings are always labeled to tell you in an instant whether any bearing you take to the prominent object will be dangerous. Prefix your danger bearing with NMT (Not More Than) for dangers to port. Prefix your danger bearing with NLT (Not Less Than) for dangers to starboard.

Notice in the illustration the danger lies to starboard, so we prefix the danger bearing with NLT. This means any bearing we take to the prominent object--in this case a Tank--should read 045M or higher. If we take a bearing of 045M, 046M, 047M, 048M… we are sailing in deep water. If we take a bearing less than 045M (i.e. 044, 043, 042…), we are standing into danger, and must change course away from the danger.

5. Take Bearings Often:

As soon as you sight your prominent object, start taking danger bearings. Continue to take bearings until you are clear of the danger. Follow the rule on top of your line. Adjust your sailing course toward the wind or current in order to compensate for drift or leeway. If at any time, your bearings fail to meet the danger bearing criteria written on top of the danger bearing line, turn hard away from the danger.

In the illustration, if we take a bearing to the Tank of 043M, this indicates we are standing into danger. We must turn hard away from the danger and steer for deeper water. We will continue to shoot bearings to the Tank until the hand bearing compass reads 045M or more. That way we will know right away as soon as we are back in safe water.

~~~~~~~~~~~~~~~~~~~~

Boost your sailing navigation skills with simple, foolproof methods like the humble danger bearing. Keep your sailing boats and sailing crew or partner safe in the waters of the world—wherever you choose to cruise!

John Jamieson (Captain John) with 25+ years of experience shows you the no-nonsense cruising skills you need beyond sailing school. Visit his website at www.skippertips.com for a free sailing tips newsletter. Become a member for instant access to 425+ articles, instructional videos, newsletters, e-Books, and live discussion forums.

Related Articles

Sailing in the Olympics beyond 2016 - A double Olympic medalist's view
Bruce Kendall takes a look at what he believes Sailing needs to do to survive beyond the 2016 Olympics. Gold and Bronze medalist and multiple world boardsailing/windsurfer champion, Bruce Kendall takes a look at what he believes Sailing needs to do to survive beyond the 2016 Olympics. A key driver is the signalled intention by the International Olympic Committee to select a basket of events that will be contested.
Posted today at 12:16 pm
From Olympic flag to Olympic Gold and maybe another
The Sydney Olympics was a Sailing double 470 Gold event for Australia. Having won the 420 World Championship in 2000, the feeder class to the 470, while still at school in Australia young Matt Belcher was given the honour of carrying the Olympic flag during the closing ceremony of the Sydney 2000 Olympics.
Posted on 28 Apr
Pantaenius – Smooth sailing is more than a favourable weather forecast
Pantaenius get ready to launch into their fourth year operating in Australia As Pantaenius get ready to launch into their fourth year operating in Australia, we get to see why they continue to grow their happy crew of customers. Sitting down with Pantaenius Australia’s MD, Jamie MacPhail, you immediately get a sense that the smooth sailing is a direct result of both their unique product and the marketplace’s willingness to embrace the better mousetrap
Posted on 27 Apr
100 days to Rio, are there potholes and bumps ahead?
The Road to Rio 2016 still has a few curves, bumps and potholes for teams battling to win in Hyeres. The Road to Rio 2016 still has a few curves, bumps and potholes for teams battling to win in Hyeres, at some World championship events and Weymouth World Cup but for most crews.
Posted on 26 Apr
Is George Lucas a sailor?
He’s very famous for a lot of things, and justifiably so. One of them is Industrial Light and Magic He’s very famous for a lot of things, and justifiably so. One of them is Industrial Light and Magic, which has been instrumental in the making of many of the special effects that have made the digital world so impressive. Gone are the smears of Vaseline along the bottom edge of the clear filter to hide the trolley that was actually transporting Luke Skywalker’s Speeder, for instance.
Posted on 25 Apr
America's Cup - Oracle Racing win in Court but with collateral damage
Oracle Racing have had another claim against them by a former crew member dismissed. Oracle Racing have had another claim against them by a former crew member dismissed. Mitchell focussed largely on the circumstances of the matter and introduced into the public arena some interesting documents to support his claims.
Posted on 23 Apr
Thou doth protest too much, me thinks
And no, we’re not off to analyse Hamlet right away. There’ll be no surtitles popping up on the top of your screen And no, we’re not off to analyse Hamlet right away. There’ll be no surtitles popping up on the top of your screen about now. At any rate, it is simply an adaptation of Lady Gertrude’s original line. We merely seek to use it as a way to demonstrate that when there is a lot of brouhaha going on, the smoke screen ultimately ends up as a lovely, colourful flag as to the real intent behind it.
Posted on 18 Apr
Children of the Internet, Rio and Hong Kong
I have four daughters, the youngest, who in her mid 20's is a true child of the Internet. I have four daughters, the youngest, who in her mid 20's is a true child of the Internet. The kind of conversations I have with her run along these lines.... In the olden days we did not have television until I left school and they had a thing called print magazines, that reported events between two weeks and four months after they happened. And her sceptical response... Hoh! Daddy, Hoh!
Posted on 14 Apr
Can World Sailing learn from dear old Oz?
Why just lay the drop sheets out and tape up the edges of the windows for a splash of paint Some time ago now, Sail-World proposed that ISAF had a really good opportunity at hand when it morphed into World Sailing (WS). Why just lay the drop sheets out and tape up the edges of the windows for a splash of paint, when you could bring out the jackhammers and do a proper reno??? A call was issued for 200,000 sets of goggles and earmuffs to be supplied and for the real work to be commenced.
Posted on 11 Apr
World Sailing Cup V3 - A Dead Rat in a Shoe or Spring Daffodils?
While a host of major sailing events go from strength to strength, the Sailing World Cup has very major issues. Last night my Irish better half was sitting beside me on the sofa watching an Australian version of the popular TV Cooking Program My Kitchen Rules on a tablet with her headphones while I was watching Diehard II for the seventeenth time (it’s a boy thing) on TV. She suddenly spluttered and laughed, took off her headphones and motioned for me to mute Diehard. (Seriously!!)
Posted on 9 Apr
Pantaenius - Fixed ValuePacific Sailing School 660x82 1T Clewring AC72