Go Back   Cruiser Log World Cruising & Sailing Forums > Cruising Forums > General Cruising Forum
Cruiser Wiki

Join Cruiser Log Today

Reply
 
Thread Tools Search this Thread Display Modes
 
Old 02-09-2007, 11:01 PM   #1
Rear Admiral
 
Harbor_Pilot's Avatar
 
Join Date: Feb 2007
Posts: 323
Default Where Are We?

GPS or Sextant?

Is it a dieing bred to navigate via the sky, sextant and charts?

Are sailors relying solely on GPS with no alternate methods or back up systems?
__________________

__________________
When in doubt, do the right thing.

Harbor_Pilot is offline   Reply With Quote
Old 02-09-2007, 11:36 PM   #2
Commander
 
Spike_dawg's Avatar
 
Join Date: Jan 2006
Posts: 145
Default

The backup is to have a handheld GPS. Much safer and far more accurate. Cost less and you don't have to worry about being 50 miles off in position and trying to keep a dead reckoning log. You know your position to within a few meters anytime of the day or night, cloudy skies, bad weather, etc. Quicker, cheaper, more accurate and alwats up to date.

I don't use Loran, morse code on the radio, wood blocks, or a horse and buggy. It's called progress.
__________________

__________________
Spike_dawg is offline   Reply With Quote
Old 02-09-2007, 11:50 PM   #3
imported_admin
Guest
 
Posts: n/a
Default

Just to add to Spike_dawg's good advice:

The back-up (second) GPS will normally be a hand-held and NOT a second boat GPS - DIFFERENT power source.

.
__________________
  Reply With Quote
Old 02-10-2007, 04:54 AM   #4
Rear Admiral
 
Harbor_Pilot's Avatar
 
Join Date: Feb 2007
Posts: 323
Default

Spike dawg, and Admin,

Thanks. I like the answers and the solution. I like progress and understand that concept.

I really am not super motived to learn navigation with a sextant, being a product of the technological age, yet feel I must, at least should.

My training and expeiance tells me to plan for and have backups and alternate plans.

Should one loose the main boat and it's systems, the handheld would be useable in the life raft. Provided one gets it there in working order, batteries included. At that point it may or may not be to important to know "Where are we?" compared to: was the MAY DAY signal received, are we sending a signal, when may help arrive, and how much water, food and floatation did we save?
__________________
When in doubt, do the right thing.

Harbor_Pilot is offline   Reply With Quote
Old 02-10-2007, 06:00 AM   #5
Admiral
 
Trim50's Avatar
 
Join Date: Feb 2006
Home Port: Who cares really...
Vessel Name: T
Posts: 1,215
Send a message via Yahoo to Trim50
Default

Aqua Man

First, if you haven't already, go take some basic Rules of the Road and DR Navigation courses.

Then, buy Navigator 4.5 with Star Finder. It is much better than Star Pilot IMHO. It is written by a Brazilian programmer Omar Reis with a lot of talent and the cost is less than half that of Star Pilot. It makes learning to use your Sextant quick and easy.

http://www.tecepe.com.br/nav/

Using the sextant is a great way to pass the time while cruising and it gives you a nice warm since of security that you have the ability to navigate without GPS.

Cheers,

Ken
__________________
[
Trim50 is offline   Reply With Quote
Old 02-10-2007, 06:13 AM   #6
Admiral
 
Auzzee's Avatar
 
Join Date: Jan 2005
Home Port: Darwin
Vessel Name: Sandettie
Posts: 1,727
Default

Sextant navigation is an oddity in the modern world, but I still enjoy taking sights to 'prove the GPS' on occasion. It can be fun also to plot position using the sextant to determine recripocal bearings from shore based objects when coastal cruising, and there is no better way to see a solar eclipse than through the filters on your sextant.

However, I trust the GPS far more than the sextant and I reiterate, in my opinion the sextant in today's age is an oddity.

David
__________________
"if at first you don't succeed....Redefine success"!


Auzzee is offline   Reply With Quote
Old 02-10-2007, 06:24 AM   #7
Admiral
 
Trim50's Avatar
 
Join Date: Feb 2006
Home Port: Who cares really...
Vessel Name: T
Posts: 1,215
Send a message via Yahoo to Trim50
Default

Some may argue otherwise, but I strongly believe a severe solar storm could leave a large number of cruisers flying blind on the open seas one day.

================================================== =================

SOLAR flares can drown out GPS signals with potentially serious consequences for airlines, emergency services, and anyone relying on satellite navigation.

It turns out these bursts of charged particles, which produce auroras and geomagnetic storms, also generate radio waves in the 1.2 and 1.6-gigahertz bands used by GPS.

How was such a clash missed? Because GPS receivers only became common during a period of low solar activity. By 2011 solar flares will reach the peak of their cycle and receivers will likely fail. Or so Alessandro Cerruti of Cornell University, New York, told a meeting of the Institute of Navigation in Fort Worth, Texas, last week. The only solution would be to redesign GPS receivers or satellites, which may not be practical, says Cerruti.

From issue 2572 of New Scientist magazine, 07 October 2006, page 27
__________________
[
Trim50 is offline   Reply With Quote
Old 02-10-2007, 06:58 AM   #8
Admiral
 
Trim50's Avatar
 
Join Date: Feb 2006
Home Port: Who cares really...
Vessel Name: T
Posts: 1,215
Send a message via Yahoo to Trim50
Default

Another good article:

http://science.nasa.gov/headlines/y2006/10...tormwarning.htm
__________________
[
Trim50 is offline   Reply With Quote
Old 02-10-2007, 08:25 PM   #9
imported_admin
Guest
 
Posts: n/a
Default

It is important to still plot your position on a paper chart - we did it every hour.
__________________
  Reply With Quote
Old 02-11-2007, 01:16 AM   #10
Admiral
 
Trim50's Avatar
 
Join Date: Feb 2006
Home Port: Who cares really...
Vessel Name: T
Posts: 1,215
Send a message via Yahoo to Trim50
Default

No doubt! I just wonder how many sailors actually do it.
__________________
[
Trim50 is offline   Reply With Quote
Old 02-11-2007, 02:41 AM   #11
Rear Admiral
 
Swagman's Avatar
 
Join Date: Sep 2005
Posts: 349
Default

We rely soley on GPS - and have two backs up - one with differing power source. We also do note position / course / speed each hour to paper just in case we need to revert from plotter to paper chart. Never yet had to do so.

However, have seen GPS switched off for a period around start of first gulf war which was a bit diconcerting as we were out of sight of land, racing, and not kept paper records of positions. Fortunately our estimates were not too far off and we hit shore about right spot.

But to counter those who warn GPS might fail for whatever reason - lets not forget the sun and a sextant are not 100%` either. If you've a week of cloud and no ability to take sun or star sights - your sextant is only useful as a backscratcher!!

Cheers

JOHN
__________________
Boring blog at http://www.yotblog.com/swagman
Swagman is offline   Reply With Quote
Old 02-11-2007, 05:52 AM   #12
Moderator
 
JeanneP's Avatar
 
Join Date: Jul 2004
Posts: 2,098
Default

Quote:
Originally Posted by name='Converted Post'
Originally posted by Trim50

No doubt! I just wonder how many sailors actually do it.
When the Magellan GPS first came out, Peter bought one, ridiculously expensive as they were. In 1990 we were sailing up the Costa Rican coast when we heard two boats, sounding a bit panicky, complain that their GPS had stopped giving positions. The US military was fiddling with the satellite transmissions and there were limited positions given over a period of several days. One could query the GPS for the schedule of the satellite down time, so there should not have been so much worry on the part of these boats. They obviously had not been keeping a DR log, and I got the impression they didn't know how to plot a DR course.

I don't expend much energy feeling sympathy for people who leave the comfort of modern civilization without preparing themselves for the consequences of that decision. Yet marketing departments of the various GPS manufacturers aren't about to warn their potential customers of the problems they might have. Most navigation courses, though, do emphasize the importance of preparation and course logs.

Listening to panicked voices on the VHF, hearing about the silly mistakes that people make on the water, and watching boats follow their chart plotter slavishly, afraid to deviate course even by a degree, I would say that there are too many people out there without the necessary preparation to go offshore. As a woman, it worries me that many couples leave all the navigation to the man, with the woman totally clueless as to how to get from point A to point B.

That's not to say that I advocate carrying a sextant. Ours sat in its case and was only taken out when Peter felt like exercising his brain a bit, and fortunately we never had to rely on a fix from it because to use it properly one must continually keep up one's skills in using it. I'm not sure that it's worth it. Carrying more than one GPS is a reasonable precaution. Carrying paper charts is, IMO, a necessity. Understanding the basics of navigation is most important. If you have confidence in your compass you can usually plot a DR course that will get you to land, though not necessarily the land you were planning to go to. And I'd hate to have to navigate the Pacific Ocean without electronics aids, but it's been done for thousands of years.
__________________
In 1986 we went cruising for a few years. After 20 years and 50+ countries and several oceans, we are STILL "cruising for a few years".

SY WATERMELON |
MV WATERMELON (New) | Cruiser's Dictionary, free ebook

= Cruiser's Dictionary, North America,
JeanneP is offline   Reply With Quote
Old 02-11-2007, 07:39 AM   #13
Ensign
 
Join Date: Jan 2007
Posts: 29
Default

Quote:
As a woman, it worries me that many couples leave all the navigation to the man, with the woman totally clueless as to how to get from point A to point B.
Now thats funny! My WIFE is the navigator and radar expert. I have very little experience navigating. I can find my way looking at a chartplotter but thats it. Of course, I will be taking navigation classes in the near future. She is going to take a diesel engine course since that is my strong point.... RT
__________________
1983 Ericson 381
rwthomas1 is offline   Reply With Quote
Old 02-11-2007, 09:51 AM   #14
Moderator
 
JeanneP's Avatar
 
Join Date: Jul 2004
Posts: 2,098
Default

rw, good for both of you.
__________________

__________________
In 1986 we went cruising for a few years. After 20 years and 50+ countries and several oceans, we are STILL "cruising for a few years".

SY WATERMELON |
MV WATERMELON (New) | Cruiser's Dictionary, free ebook

= Cruiser's Dictionary, North America,
JeanneP is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

RV & Travel Trailer Communities

Our RV & Travel Trailer sites encompasses virtually all types of Recreational Vehicles, from brand-specific to general RV communities.

» More about our RV Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities


All times are GMT. The time now is 03:16 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.0