Interesting comments

[Guest]

"What I'd say to them is to do a day skipper course and learn about safety on the water, know the local geography, have a marine chart map and all the necessary equipment like a GPS, depth sounder, VHF, radio, check your batteries are charged and check the fuel before you go."

http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=10754438

 

GPS and Depth sounder are 'necessary equipment'?

The rest yes probably but those 2, knot to sure I'd go that far.

 

But then we see this in the latest Briefings -

A warning about GPS reliance

 

From Inspector’s Quarterly, by Michael Churchouse: The chairman of the working group GNSS (Global Navigation Satellite System) Dr Martyn Thomas points out that GPS containing equipment has become so cheap that we have become blindly reliant on them. He points out that many sailors are not conversant with alternative methods of navigation, many are not capable of carrying out coastal navigation and very few can handle celestial navigation.

 

There have been a number of groundings locally in NZ and Australia because of sailors’ blind reliance on GPS. The recent Flinders Islet tragedy where the yacht Pricewaterhouse Coopers using a chart plotter only, struck the island so solidly that many of the 18 crew members were lucky enough to jump off on to the rocks, is just one example. Unfortunately two of the crew did not survive.

 

Professor Andrew Dempster of Australia’s University of New South Wales also points out that the low-powered GPS signals are easily drowned out by other sources, natural ones such as solar flares and man made ones with poorly controlled signals emanating from television towers, laptops, MP3 players even mobile satellite services, and increasingly more importantly, deliberate criminal jamming and spoofing using cheaply obtained jamming units. Spoofing is where a false GPS signal is created.

 

A very good comment I thought. I'm knot sure it should be associated or at least next to a write up about the Simrad R3 Oppies though as I very much doubt a GPS was to blame for any of those dramas, besides all were with boats with very experienced crews who, in my opinion, just got caught by a 'sh*t happens event'. I sure wouldn't regard any of them as loose or silly units more than I would hard racers who just had a bad bad day, it can happen to any of us.

 

One outfit saying GPS is a necessary and one saying use them with caution. I'm sure the CG dude has nothing but the best intentions but I think I'd listen to Mr Churchouse first.

 

For a new boater reading both of those I'm sure there would be a WTF? factor.

[Guest]

They certainly lacked experience, but buying trinkets and gadgets won't make up for it.

[Guest]

Yeap, the dudes in the tinny do sound like they were found lacking big time and in many ways.

[wheels 543]

For the Herald story, I think the idea of GPS would be so they could tell Coastgaurd where they were. They had no clue obviously. I also doubt if they had a paper chart, that they would have had anymore of a clue either.

As for the Race yacht story, the mistake was not with the GPS, or having one, nor in it's accuracy. The mistake was that no one was maintaning a watch. If they had, then they would have seen the Island. Even if the GPS was innacurate, it could not be that far off accuracy to not have someone take note of an Island and poke their head up and see that they would or would not miss it. So surely they could not have been paying attention to the GPS either.

[Guest]

Again - gadgets won't compensate for other failings.

[Guest]

The 2 yacht incidents had zero to do with GPS or watch keeping, both were racing incidents as I understand it, at least one sure was. When you push hard things happen and you push boundaries at times when in the heat of battle. Most of the time you get away with it but occasionally you just don't. We all have done it, do do it and will continue to do it. 99% who do will get home quite happily but occasional one or 2 of us won't.

 

My post was more to do with their semi-conflicting nature, the idea CG thinks GPS is a necessary must have item and the 2nd quote was just very interesting as I've always thought and work along those lines i.e. GPS isn't super duper accurate at times.

 

That jambing comment is a bit spooky though.

[Guest]

Sorry, I was thinking of the Flinders Is crash - I'll just shut up now.

[wheels 543]

Flinders is what I was refering to too.

I guess other signals if they are strong enough could upset GPS, but the way the signal works, it is very robust amid all the background "noise". Plus it is constantly updating, so if one update is missed, the next tends to make up for it. Pluse there are usually(usually, although not always) more than 4 birds being received. So dropouts from one or two tend to be not a biggy.

Apart form military, I can't think of any reason why a criminal would want to jam a GPS signal though. But the US military don't really play around with it much anymore.

[Guest]

Sorry, I was thinking of the R3 crashes - I'll just shut up as well now.

 

Don't suppose you saw that Invisible World programme last night, the one with Richard Hammond chatting. You see the huge amount of radio waves all around us these days, huge and all of it* man made. Surely nothing good can come of that.

 

* - bar the very very little generated by lighten strikes and the odd thing like that.

[Guest]

Surely safer with a gps onboard. Most of the time you can describe your position down to a few meters. If someone's having a heart attack that would surely save time for example.

[wheels 543]

The radio telescopes receive signals, not transmit. Not to say though, that there are not lots and lots of dishes around the world transmitting. But the advantage oif dishes transmitting is that they tend to be very directional and use a lot less power because of that, unlike just a tower type antennae that is omnidirectional. Plus, the higher the frequency, the less transmitting power is required. Hence transmission in AM is in 10's to 100's of Kw, FM is 10's to 100's of Watts and VHF is in 1 to 10's of Watts and so on.

But a GPS signal is Digital. Best explained is using the current Digital TV channels coming from satellites to our dishes. We have a Satellite that is transmitting on a frequency. Each channel is a digital encoding riding upon that frequency. That way many many TV and Radio channels get to be transmitted all at once and the set top box on our TV decodes all that information and pulls out of it one particular channel selected. Hence how litteraly 100's of channels can be broadcast using a narrow bandwidth of frequency.

[PaulR 3]

Report quotes: "The young men, aged 15 and 20"

 

Bulletproof, nothing is going to happen, were OK.

 

Very easy to understand. Forget heart attacks BB, never going to happen.

 

What Toys come with manuals But that's like school. Reading is boring

[TimB 7]

After an enquiry the Flinders Island incident was shown to be a combination of an over tired Skipper/navigator who didn't delegate the navigation AND a period of proven signal degredation of the GPS accuracy. The proof was from an engineer responsible for around theclock laying a water pipeline near Sydney and he noticed the GPS controlled equipment went "haywire" for a couple of hours about the time the yacht hit the rocks. They thought they were clear (going by the chart plotter) but weren't (and it was dark like the inside of a cow so no-one saw the island unitl too late).

 

The skipper was chastised for trying to do too much after a full days work, then leaving on Friday evening for an overnight race.

Timb

[Guest Rocket]

You had to take away from the Flinders Island crash that you cannot blindly follow a GPS plot.

 

I have personally seen many GPS plots showing me on land when entering narrow channels on a variety of boats. We have got lazy - you need to be on deck using your eyes! We used to sail around happily without GPSs and still can - I fear their presence has provided a huge number of people with a false sense of confidence - and led to many more inexperienced crews feeling competent enough to do anything anytime.

[smithy09 50]

I would like to see a write up on the High Voltage crash. I have heard conflicting reports, and I'm just not sure exactly what happened..

[Guest]

You had to take away from the Flinders Island crash that you cannot blindly follow a GPS plot.

 

I have personally seen many GPS plots showing me on land when entering narrow channels on a variety of boats. We have got lazy - you need to be on deck using your eyes! We used to sail around happily without GPSs and still can - I fear their presence has provided a huge number of people with a false sense of confidence - and led to many more inexperienced crews feeling competent enough to do anything anytime.

This Rocket dude is spot on and it's something I've also be saying for many years. GPS and the assorted toys do seem to make some boaters think they can go anywhere any time without observing basic boating skills i.e. using their fecking eyes would be one.

 

Ha, and this Rocket is the 3rd one I've connected with today. We had Rocket signs people in in their pimped wagon, hard case. After that we had real dinkum Rocket Scientists in, helping them with tiny strings to deploy parachutes in real dinkum rockets.

[Guest]

Hey Rocket, thats the chart not the gps!

[Guest]

Hey Rocket, thats the chart not the gps!

 

V E R Y true! Sir Peter Blakes sojurn to the antartic on TV sometime ago showed his chart plotter....... he was sailing 20nm INLAND... over MOUNTAIN RANGES!! (I want that boat! ).

Reality was the chart was based on one done in the 1800's!!!! (there are a lot that still are)

[Guest]

I think the point is that back when we had to learn navigation, you were taught to always be aware of the accuracy of the tools you were using, we would use a circle around a position to indicate any possible inaccuracy and make sure the edge of the circle never touched a hard bit.

Now you buy a chartplotter, and for five years everytime you use it it is perfect, so you believe it, then sh*t happens when the signal is degraded, or you go onto a new chart, or...............

[PaulR 3]

Now you buy a chartplotter, and for five years everytime you use it it is perfect, so you believe it, then sh*t happens when the signal is degraded, or you go onto a new chart, or...............

 

Only problem is that last step, plotting onto the paper chart, because you were watching the GPS/plotter woring and have knot written down or plotted your position regularily ( hourly, knot monthly )

 

A lot of charts have in small print adjustment / offsets that need to be applied to convert GPS positions onto the paper charts. Some of the Pacific Islands' charts are a few nmiles out

 

I would be pretty sure Blakey would have made those adjustments.

Once upon a time, we did knot have those GPS problems