News Home Video Gallery Newsletters Photo Gallery Cruising Int
Sail-World.com : The biggest question when going to sea - Where am I?
The biggest question when going to sea - Where am I?


'Using every mode available to establish and reconfirm your position (Credit: Hamish Hooper/CAMPER ETNZ/Volvo Ocean Race)'    Hamish Hooper/Camper ETNZ/Volvo Ocean Race©    Click Here to view large photo

Before technology surfaced, early mariners, over the centuries, devised many crude solutions to determine where they were in the water. The death of a friend recently on a reef in the Tuomotos, through a small miscalculation, has had me ruminating on how seafarers stayed safe over the thousands of years they have been transiting the ocean.

The Compass:
The earliest compasses were most likely invented by the Chinese in around 1050 BCE. Intriguingly, they were created first for the purposes of spiritual life or developing a feng shui environment and then only later used for navigation.

Compasses were originally developed when lodestones, a mineral that has naturally magnetized iron ore, were suspended above a board with the ability to pivot and turn. It was discovered that the stones would always point in the same direction, and align themselves with the north/south axis of the earth.

Then crude charts were drawn. The forerunner of the modern magnetic compass consisted of a magnetized needle placed in a piece of cork, which floated in a pan of water. The marked end of the needle pointed to magnetic north. This primitive form of a compass went through many changes prior to the development of the modern day instrument.

The superiority of modern equipment - with caveats:
Today it is much easier to find out where we are on earth. As well as GPS, we now have depth recorders and other electronic devices supposedly answering the question, 'Where are we?'

However, total trust in the GPS can end in tragedy on the sea - and often has. There are a number of reasons for this:

1. The GPS position being 'wrong' when related to the (correct) chart it is shown on
2. Inaccurate reading of the GPS by the skipper
3. A lightning strike destroying all metal equipment on the boat
4. Inaccurate out-of-date charting, particularly in remote areas

Good old fashioned compass -  .. .  
Back-ups - the paper chart:
When navigating large bodies of water, there is no substitute for having a paper chart readily available. Even with advanced technology, it's an excellent idea to keep track of your boat's position on paper as a back-up to your electronic equipment's information or as a starting point for doing without it when it fails.

Dead Reckoning:
The advancement of the boat's position on the chart from the last accurate position using courses steered and speed through the water is known as dead reckoning. A dead reckoning track line is drawn on the chart from a known position to your destination. To plot the direction your boat is headed on the course line, many types of course plotters may be used to determine the direction of travel by a compass rose on the chart.

With the boat's known speed and time traveled, you can plot your position on the course line -- usually hourly.

In the final analysis, it is the intelligent use of all the systems available to the seafarer which denotes good seamanship and it likely to bring the skipper and crew home safely, rather than the sophistication of the equipment available.


by Lee Mylchreest

  

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

http://www.sail-world.com/index.cfm?nid=114878

11:18 AM Mon 23 Sep 2013GMT


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







Cruising USA



Where in the world are our strongest corals? by Hanny Rivera - Cohen's Lab,








Barnacle Busting by Neil and Ley Langford,


From Penguins to Polar Bears by Cherie Winner,




Polar research: Six priorities for Antarctic science by Mahlon C. Kennicutt II and colleagues,




NCI granted dedicated VHF Channel by National Coastwatch,


Positive news for cruising boats in Greece by The Cruising Association,




















Risks to penguin populations continues by British Antarctic Survey,




Follow these tips when anchoring by Alex and Daria Blackwell,


Galley Guys meet the Spice Lady by Greg Nicoll, Andy Adams and John Armstrong,




If all else fails read the instructions!! by Stuart Carruthers, RYA Cruising Manager,




Phuket Yacht Show: new kid on the block taking on PIMEX? *Feature by Guy Nowell, Sail-World Asia and Phuket Yacht Show,






Flags at Sea, an infographic by John Tissott by Anna Parker and the Sail-World Team,




Procedures set out for waterborne visitors to Vanuatu
17-year-old RNLI volunteer saves child in first rescue mission + Video
Teen names latest RNLI Shannon class lifeboat in Poole + Video
Fascinating opportunity with OceansWatch
Fake GPS signals detected when cruising the high seas
Our new Cruising Editor editor remembers his first offshore adventure
Blue Planet Odyssey - Jimmy Cornell playing catch up on North West Pa
World ARC 2014 reaches Australia
Venezuelan Port Control lift recent port restrictions.
Seismic survey ship operating north of Aruba and Curacao
Predictwind helps you pick the best time to depart
Watch this whale lift a Kayak clear out of the water
World ARC reaches half-way point in Australia
Northern Scotland: Voyage to Orkney and Shetland Isles (Part 2) *Feature
Drowning or electric shock? What you need to know to help save a life
Costa Concordia - the $2.25 billion salvage operation ready to begin
Northern Scotland: Voyage to Orkney and Shetland Isles, more photos *Feature
Fort Lauderdale International Boat Show - New location and attractions
Long Island waters could become more taxing this summer
4.8 million Legos all at sea
Tranquil, colourful and funky, Genoa Bay is a must stop for West Coast *Feature   
Scientist pioneered tracer to reveal hidden ocean flows   
Sail-World 2.0 - the Beta version- Please take a look   
Dredging activity near corals can increase frequency of diseases   
World ARC heading out of the Pacific   
Understanding the Ocean's role in Greenland Glacier melt   
Desolation Sound added to Salish Sea Pilot free cruising guides   
Three Defensive Docking Strategies for Sailors   
Revealing report on Search for American yacht Nina released *Feature   
PredictWind's Weather Routing opens your navigation options - try it!   
Sail-World Cruising Founding Editor Nancy Knudsen says farewell   
Book review: Weather - you like it or not   
Vaavud launches generation 2 wind meter   
The drama begins - North West Passage sailors rescued from ice   
Entering an unfamiliar bay - decision time   
Baby Nemos finding their way home   
High Latitude Sailing - Book of the Week   
Will the Olympics make a difference to Rio pollution? *Feature   
Blue Planet Odyssey, around world rally, begins   
Africa Europe Cruising Challenge now open for entries   


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  

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 Cru USA
LocalAds   DE  ES  FR  IT