NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Status of Celestial Nav in 2015
From: Lu Abel
Date: 2015 Mar 7, 03:07 +0000
From: Lu Abel
Date: 2015 Mar 7, 03:07 +0000
Well put, Alex! It's nice to have a backup method of navigation, but that can simply be another GPS! Dead batteries? Carry some spares! Dead GPS? Carry a spare, it's cheaper than a sextant! But there are advantages to using a time-tested alternate way of position finding, if for no other reason than to keep the technology alive.
By the way, I notice that this topic has been Celestial NAVIGATION in 2015. While we may call it "celestial navigation" it's really celestial *position finding*
Navigation -- whether steering a ship across the ocean or driving my car to a nearby coffee shop -- involves alternating between answering two questions: "Where am I?" and "How do I get from where I am to where I want to go [safely, quickly, comfortably]?"
Pre-GPS, the navigator spent most of his/her time answering the "where am I" question using time-consuming (and ofttimes inaccurate) techniques -- bearings, advanced bearings, horizontal angles, vertical angles, chains of soundings (and on and on) for coastal navigation, celestial for offshore.
These days with the "where am I" instantly displayed on some magic electronics, the navigator can concentrate on "how do I get to where I want to go"
Or, sadly, he/she can consign that task to the black box also. Except the black box does not know of shallows, traffic to be avoided, channels, etc, etc. But that's the fault of the navigator, not the technology.
If you want a technology worse than GPS, consider AIS (the radio signalling system that all SOLAS vessels are required to have). By comparing your vessel's position and course to anothers, the system will warn of impending collisions. As a result watchstanding on many commercial vessels (especially "flag of convenience" ones) has disappeared, despite what the Navigation Rules say about using "all possible means" to ascertain if there's a risk of collision with another vessel. No visual, no radar, just AIS.
There was an incident in the English Channel last year where a tug and barge not equipped with AIS were run down by a freighter, and I've heard of incidents here in the US between commercial vessels and recreational vessels.
I know several offshore sailors who say they absolutely would not go offshore these days without an AIS system because so many commercial ships simply turn on their autopilots and wait for their AIS to tell them of any collision risk. The offshore sailing community is convinced that a high percentage of the 40 or 50 vessels that simply disappear each year may be victims of rundowns by ships on autopilot.
From: Alexandre Eremenko <NoReply_Eremenko@fer3.com>
To: luabel@ymail.com
Sent: Friday, March 6, 2015 12:01 PM
Subject: [NavList] Re: Status of Celestial Nav in 2015
On my opinion, one cannot justify CelNav by any "practical need" like backup of GPS etc. There is no doubt one can navigate effectively without it. I think the true reason why people do it is completely different. It is similar to the reason why people sail under sails. No one justifies this by any practical advantages of traveling under sail in comparison with taking an airplane, or a motor ship. Motor ships and airplanes take you from one place to another faster, cheaper, safer and and with more comfort. Nevertheless many people sail sailboats. Because it is fun by itself, not because it is an effective mean of transportation. Same with Cel Nav. Alex.
