So its not just our imagination, and can be dangerous!

www.news.com.au/technology/innovation/military/gps-signals-jammed-norway-finland-warn-pilots-russia-may-blind-their-navigation-systems/news-story/ee28be793012e9b9e66d59ffba439242

GPS is handy but I believe it still does not stand in a court of law.

There is nothing really hard to do when coastal navigating with a bearing compass, sounder, log, parallel rule, dividers and paper charts.

People these days are more mentally lazy than they are physically lazy.

Well, Trek, you might remember the posts on the vulnerability of the GPS system to terrorist interference. I was hooted down by the non-believers in Russian and Chinese evil and general belligerence.
Because they are evil and belligerent, no doubt!

Well, here we go again, and we are still not arming ourselves - mentally, morally, economically as well as physically - against those two potential terroristic states Russia and China - and their interference.
The US is the third side of the triangle but at least it is on our side, we hope.

No, we cower, we appease and assuage to their demands and to our "economic interests" which is the rope on which we are going to be hanging sooner or later. By that time free GPS will be just a story from the past.

Australians who had no first hand experience with communist states and their politics and philosophy - Marx, Engels, Lenin, Mao - have no idea of their deep seated hatred of their opposites and twisted ideology. Their philosophy has logical continuation in the new governments and political leadership of those two countries, openly communist or otherwise and their satellites.
They are the same wolfs in different fleece.

The clandestine, malignant interference with - beside the GPS or GLONASS systems - anything and everything in their interest is not just possible, it is a given. They are dwelling on it ever since they existed.
Just think of the USSR's huge operation to interfere with Radio Free Europe and Voice Of America. They don't give a hoot about international treaties, politics, law at all, less their interest requires so.
Reagan was right when he called the USSR "the evil empire" . Why would it be different with the GPS system?

The interference with the GPS system is not just likely in case of hostilities, but it is a necessity. If one is foolish enough to deny this, one does so at his own peril.

Cherish the old maps, charts and brush up on your navigational skills, asap.

Yeah, it ain't funny thou, when the satellites are blown up and 300 feet below your keel!

Yeah, Toph, aren't you aware of the fact, "hope dies last!"?

I am not worried of the system as such,
I am worried for it!

Even the Navy now relies on GPS and chart plotters. A visit to an Armidale Class Patrol Boat will show you how it is done now. I doubt the Navy would rely on something that isn't legal.
The satellite navigation system in the early 90s being used by yachts probably was not GPS but rather transit nav. Transit nav relied on the proximity of the satellites to the platform so positions could be far in error or very close. It was transit nav back then that gave error probability circles.
Although GPS was allowed for civilian use in the 80s it wasn't fully operational until 1995 and didn't come into common civilian use until the mid 90s.
There are far more opportunities for navigation errors using manual nav than there are using GPS and chart plotters. I can attest to both being a professional navigator in my past using both systems. My big stuff ups were due to errors in plotting, avoided now with chart plotters and GPS.

But the possibility of failure of the GPS system is all that is keeping some of the old buggers going! They're just dying to be able to say, "I told you so" as they wave their brass dividers for the last time!

Chuckles intended.

Bristol

There is a book called Ghost Fleet.
www.abc.net.au/radionational/programs/latenightlive/peter-w-singer-ghost-fleet/6726332

It envisions a clash between China and the US that, shell we say, gets out of hand.
The first thing to go are the satellites.
Knocking out communications and tracking systems would logically seem the first choice in any major conflict.
Unfortunately, the debris from this sort of scenario makes the most useful orbits, useless.
Back to cables for communications and sextant for navigation.
That is if there is a back to.

A great read.

gary

In the last few outings offshore I've noticed twice a fairly significant degradation of both GPS' to the point of losing synch. Worst case was for maybe 45 mins., other was no more than 10-15 mins.
A check of the GPS showed both times there were enough satellites visible, but all were low enough on the horizon to cause a loss of synch.

Bananabender said..
Let's see , chart says I need to steer 5 degrees true . Now compass rose says variation 11 degrees east .

I abide by the rule that True Virgins Make Dull Company ie, True + or - Variation = Magnetic + or - Deviation = Compass.

Simple stuff!!

When coastal navigating I like doing my three bearing and running fixes etc to compare the GPS against to determine how inaccurate the GPS is day to day.

I love my I pad while sailing we just delivered a boat up from Sydney last weekend never more than 250 meters offshore as the current was ripping I pad in cockpit at all times lots of ticking off on the chart as well I always remember shockwave being written off on the rocks people dying because the yanks had disabled the gps while they were killing arabs this was the stated reason at the inquiry
conclusion gps awesome don't rely on it

cisco said..

Bananabender said..
Let's see , chart says I need to steer 5 degrees true . Now compass rose says variation 11 degrees east .

I abide by the rule that True Virgins Make Dull Company ie, True + or - Variation = Magnetic + or - Deviation = Compass.

Simple stuff!!

When coastal navigating I like doing my three bearing and running fixes etc to compare the GPS against to determine how inaccurate the GPS is day to day.

You reckon a running fix will be more accurate than GPS? Errors in taking bearings, chart errors, plotting errors and in estimating speed oover the ground add up to big errors. You are really checking how inaccurate your fixing is compared to GPS.

When l came down the NSW coast l could tell where we were by looking out the window!

Remember

GPS is an Aid to Navigation. Mouse is right!!

To be clear, for many years I derided GPS and relied on traditional nav but learnt my lesson a few times.

I now use GPS as the primary but I keep a chart plot as well and even take bearings, just for fun.

Mouse is right - when I'm on watch & I know where I am by, well, watching!

Not much use out of sight of land, of course.

Cheers

Bristol