MarineBusiness-World.com
 
 
News Home Cruising USA Cruising Int Photo 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.







Cruising Canada









Springtime Greening: Boaters Tips for Earth Day by BoatUS Foundation/Sail-World Cruising,








How sailors really do have a voice in the future of our oceans by Sandra Whitehouse, Sailors for the Sea,


Message-in-a-bottle record - 102 years by AFP/Sail-World Cruising,










Canadian solo sailor rescued north of Auckland by Sail-World Cruising round-up,


















Free online fuel spill course - how much do you know? by BoatUS Foundation/Sail-World Cruising,












Life-shattering event sends 'rookie' couple sailing the world by Asia News Network/Sail-World Cruising,








3,200-year-old boat found in Croatian waters
Product of the Week: the LineGrabber
Mediterranean Mooring - How to moor stern-to to a dock or quay
Canadian storm bomb threat - sailors advised: get off the water!
Carbon monoxide poisoning - is it possible on YOUR boat?
Sailing family condemmed for taking 3-year-old on circumnavigation
New contract-free plan for satellite communicator on your smart phone
Yacht of the Week: The Dashew creation: no sails, but eco-friendly
No laughing! Sailing mistakes I don't want to make
Destination: From Moscow Sea to the White Sea
Land sailors of India on adventure across the Rann
A Paint App to (almost) replace your marine store assistant
Air warms but water slower - be careful, sailors, of hypothermia
Volunteer Canadian rescue team homeless - any offers?
Hilary Lister and Nashwa Al Kindi set a new trans-ocean record
How to anchor and 'never utter a word'
Non-pyrotechnic flares for my boat - Can I or can't I?
Health benefits of sailing
Cruising in the Maldives - some nuts and bolts
ISAF Guide to Offshore Personal Safety for Racing and Cruising
Halyard Tension - a video   
Winchrite - for lazy days or extra muscle-power   
Researcher examines 'current leaks' that may change the way you sail   
Paris off to attempt to circumnavigate the world again   
Need a tow from that helicopter? - watch the video and don't laugh   
Certain oil spill products shown to be ineffective and toxic + Video   
The Constrictor: a powerful 'Queen' of sailing knots!   
Boat painting - simple but best tips   
'It's never just one thing' - Swedish sailors rescued   
Book of the Week: From the Galley of...   
Two brave women to sail India to Oman across Arabian Sea   
Rhode Island's Classic Yacht Symposium - Registration opens   
Another rescue for second-time unlucky solo sailor   
New York to San Fran record attempt - Maserati reaches the Horn   
Finally the book:HMS Bounty, Disaster and Survival in Superstorm Sandy   
Yachts impounded in Mexico - the agony goes on...   
Students achieve robot boat Atlantic Crossing - but not as planned   
Solar vessel nominated for Engineers Prize   
Endurance Award for cruising sailors, new worldwide award for 2014   
It's coming. Dodgers/biminis to be solar power producers   


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  



















 
Our Advertisers are committed to our sport, please support them!
This site and its contents are © Copyright TetraMedia Pty. Ltd and/or the original author, photographer etc. All Rights Reserved.

Photographs are copyright by law. If you wish to use or buy a photograph you must contact the photographer directly (there is a hyperlink in most cases to their website, or do a Google search.) with your request.

Please do not contact Sail-World.com as we cannot give permission for use of other photographer’s images.

Only if the photographer named on the image is Sail-world.com, Powerboat-world.com, Marinebusiness-world.com or NZBoating-World.com.
Contact us .
Ph: +61 2 8006 1873 or complete our feedback form    Contact us .
   View our Privacy Policy.    [Go Home]     [  Banner Advertising Specification]    [Bot Archive ]

Customised news feeds -Marine Industry companies, Clubs and Associations have their own customised version of our news feed on their website.
Look_here_to_see_examples

X6XL NEW Cru CA