sail-world.com
 
 
News Home Cruising Photo Gallery Video Gallery
Sail-World.com : Know these seven danger nautical chart symbols!
Know these seven danger nautical chart symbols!


'Deadly Danger Symbols'    Captain John Jamieson

Could you glance at your chart or plotter and identify--in just seconds--the seven vital danger symbols that could rip a hole in your hull, damage your keel, bend a propeller shaft, mangle a propeller, or cause you to go aground?

There are dozens of danger symbols used on nautical charts today, but here are some of the more common ones. Know these 'ship killers' to stay safer on the waters of the world wherever you choose to sail or cruise.

1. Rocks
Note how the basic rock symbol looks like a plus sign. This means a rock that's beneath the water surface all the time. A symbol that looks like an asterisk means the rock will uncover (become visible) at low tide. A plus sign with dots in the corners means the rock lies just beneath the surface, even at low tide.

2. Islets (small islands)
Small islands--called 'islets'--are common in the Bahamas, Caribbean, and Pacific. Islets surrounded by a solid line are visible at all tidal stages. A number indicates the maximum height at high tide (or charted datum). Islets surrounded by a wavy, squiggly line cover and uncover with the tide. At higher tides, the islet will be covered. A number indicates its height above water when uncovered at lower tidal stages.

3. Breakers
Breakers form when ocean swell meets a sea bottom that's only one to two times their height. For example, if a two foot swell travels over a bottom two to four feet deep, it will break.

Breakers are dangerous to any small craft because they can cause loss of rudder or propeller control.

Stay clear of any symbol like that shown in the illustration above. You may also see the abbreviation 'Br' used alone without the symbol.

4. Coral Reefs
The world's most popular cruising grounds--Bahamas, Caribbean islands, and Pacific atolls--also contain some of the most dangerous waters. Study your navigational chart with care and look for the 'Co' abbreviation close to any rock or islet symbol.

5. Obstructions
Easy to miss on a nautical or electronic chart display, obstructions can cause damage to propellers, shafts, and keels. Many charts use only an abbreviation 'Obstn' to warn mariners. Dots around a circle mean an unknown hazard lurks beneath the surface. Tiny enclosed circles could be broken stumps, old piling remnants, or submerged poles and posts.

6. Wrecks
Fish-bones and sunken-hull illustrations make up the most common wreck symbols. Fish-bones without dots are safe to sail across. Cartographers put these on charts to warn commercial fishing trawlers not to drag nets and to caution ships not to anchor. Give fish-bones surrounded by dots or sunken-hull symbols a wide berth to avoid hull damage.

7. Spoil Area
Deadlier than the plague, identify, highlight, and stay clear of dashed outlines with descriptions like 'Spoil Area', 'Fish Haven', 'Fish Traps', or 'Dumping Ground'. Ever wonder where all those old cars and trucks, building material, or garbage goes? Now you know! Spoil areas never show soundings because depths change all the time.

Danger Abbreviations You Need to Know
Familiarize yourself with the danger abbreviations used with or without the symbols described above. Study these until you know them at-a-glance:

Rk, R or Rks - Rock or Rocks
Hk or Wk - Hulk or Wreck
Obstn - Submerged Obstruction
Co - Coral

Foul - Foul Ground
These additional abbreviations may be found alongside any danger symbol, or they may stand alone. For instance 'Shoal Rep' means that shallow water was reported ('Rep') at that position by a mariner, but it has not been surveyed. Stay clear of any area on your navigation chart marked by these abbreviations.

PA - Position Approximate
PD - Position Doubtful
ED - Existence Doubtful
Rep - Reported
SD - Sounding Doubtful

Now you know how to identify any of the seven danger group symbols on any sailing chart in the world. Use these chart navigation secrets to give you the edge and keep your crew safe and sound wherever you choose to cruise.

Learn more about nautical chart symbols and abbreviations. Download the free publication 'Chart No. 1: Nautical Chart Symbols, Abbreviations and Terms', here.

John Jamieson (Captain John) with 25+ years of experience shows you the no-nonsense cruising skills you need for safer sailing worldwide. Visit his website at www.skippertips.com. Sign up for the Free, highly popular weekly 'Captain John's Sailing Tip-of-the-Week'. Discover how you can gain instant access to hundreds of sailing articles, videos, and e-Books!


by John Jamieson

  

Click on the FB Like link to post this story to your FB wall

http://www.sail-world.com/index.cfm?nid=107197

10:47 PM Tue 5 Mar 2013GMT


Click here for printer friendly version
Click here to send us feedback or comments about this story.







News - USA and the World









Fort Lauderdale International Boat Show - 13 things to See and do by Fort Lauderdale International Boat Show,


Volvo Ocean Race: Update from Team Vestas Wind in images by Richard Gladwell/Sail-World.com/nz,








Audi Melges 20 World Championship - Classic Garda conditions on day 2 by International Audi Melges 20 Class Association,
























Audi Melges 20 World Championship - Alessandro Rombelli's 'STIG' leads by International Audi Melges 20 Class Association,
























2014 Audi Melges 20 World Championship - It's go time in Garda
2nd Annual Keith Dinsmoor Regatta September 13-14
Aldo Alessio Regatta - Three days of tight racing
PWA Alacati World Cup - First blood to Van Der Steen and Offringa
Oakcliff Sailing hosts the Nacra 17, 49er and 49erFX Nationals + Video
International 18ft Skiff Regatta underway on San Francisco Bay
Maxi Yacht Rolex Cup 2014 - Quality fleet for Maxi Classic
Sailing Champions League - which is Europe's best sailing club?
Weta fun at the Wine & Roses Regatta
Extreme Sailing Series: The Wave, Muscat claims victory on Cardiff Bay
International 14 World Championships 2015: Not just for boys
Rio de Janeiro achieves 50% treatment of sewage outflow *Feature
2014 AWT Quatro Desert Showdown - Event memorable videos
2014 18' Skiff Int Regatta: Day 1 at San Francisco - Reversal on beach
Emirates Team NZ: Last race boost cannot save team from table bottom
PWA Alacati World Cup - Furious slalom is upon us
J/111 World Championships - The Winner is Shmokin Joe!
J/24 US National Championship - Victory for Will Welles’ Cougar
Extreme Sailing Series: View the Final Day's action - Replay
NYYC Grandmasters Team Race - Reign continues for Noroton Yacht Club
WSSR announces new World Record Around Britain and Ireland   
IFDS Worlds 2014 - Final day photos by Tim Wilkes   
2014 Detroit Cup - Morvan wins   
Newport Bucket Regatta 2014 -Images by George Bekris   
IFDS Worlds 2014 - Final report: USA qualifies for Rio 2016   
Extreme Sailing Series: Absent With-Out Leave – Ben Ainslie Racing   
2014 IFDS World Championship - New champions claim medals   
2014 IFDS World Championships - Sunday’s race images by Tim Wilkes   
Shark World Championships underway in Toronto   
Anna Tunnicliffe: Alinghi second o'all - Extreme Sailing Series, Day 3   
Formula Kite World Championships - Nocher and Bridge crowned Champions   
Emirates Team NZ: Frustrating Day 3 in Extreme Sailing Series, Cardiff   
Extreme Sailing Series: Light winds help The Wave Muscat - Day 3   
Extreme Sailing Series 2014 Act five - Absent without leave – the wind   
IFDS Worlds 2014 - Images: Race day five   
Herreshoff Classic Regatta 2014 - Images by Ingrid Abery   
Youth Olympics - Gold to Argentinean and Chinese Techno 293 racers   
Youth Olympics Games Nanjing - Double Youth Olympic Gold for Singapore   
Sevenstar Round Britain and Ireland Race 2014 - Two Handers celebrate   
Audi Melges 20 U.S. National Championship 2014 - Brazilian dance party   


For this week's complete news stories select    Last 7 Days
   Search All News
For last month's complete news stories select    Last 30 Days
   Archive News







Sail-World.com  


















Switch Default Region to:

Social Media

Asia

Australia

Canada

Europe

New Zealand

United Kingdom


http://www.sail-world.com/event_images/image/Twitter_logo_small.png http://www.sail-world.com/event_images/image/FaceBook-icon.png  http://www.sail-world.com/event_images/image/RSS-Icon.png

United States

Cruising Northern

Cruising Southern

MarineBusiness World

PowerBoat World

FishingBoating World

 

Contact

Commercial

News

Search

Contact Us

Advertisers Information

Submit news/events

Search Stories/Text

Feedback

Advertisers Directory

Newsletter Archive

Photo Gallery

 

Banner Advertising Details

Newsletter Subscribe

Video Gallery

Policies

 

 

 

Privacy Policy

 

 


Cookie Policy

 

 



This site and its contents are © Copyright TetraMedia and/or the original author, photographer etc. All Rights Reserved.  Photographs are copyright by law.  If you wish to use or buy a photograph contact the photographer directly.
XLXL NEW US
LocalAds   DE  ES  FR  IT