Blind Faith in GPS

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mirabriani

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I have a friend who has recently bought a GPS.
He is convinced that the GPS will "automatically allow for leeway and tidal drift"
and therefore he will not need to do his own calculations.
He did his coastal skipper at the same time as me and was quite proficient
My worries are that;-
1 If he persists he may run aground or strike an obstruction
2 He is open to accusations of not having a proper passage plan
3 He is already prone to relying on his autohelm, which coupled with
incorrect use of GPS, will result in disaster
I often cruise in his company and I am genuinely worried for him and
his disabled wife's safety. He is stubborn and I cannot convince him.
I am relying on forum members to advise.
Thank you in anticipation
Briani

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Well, of course he is quite right! BUT...these gadgets DO break down.
If he wants to follow the dictates of good seamanship, then he must have an alternative non-electronic method of navigation.

This is not a matter of opinion or stubborness: its just fact as determined by generations of professional seafarers!

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Hi,

How long has he been sailing?
Does he ever transpose his position onto charts?
Is his autohelm interfaced in such a way that any XTE is corrected automagically?

I am not sure what you mean by "prone to relying on his autohelm". Even when I sail with my family I pretty much sail alone. The autohelm enables me to enjoy my time a little more. Clearly if it is just him and his disabled missus he is also sailing shorthanded. You will not find many shorthanded sailors that don't rely on some form of electronic wizardry. At least your chum has had the common sense to do the courses.

Everyone has their own comfort zones, yours seems very different to his. Rest assured both yours and his comfort zones will change as your sailing experiences grow.

Let him get on with it. It sounds like he has enough to be dealing with.

Regards,

P


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Can only wish you luck! I 'sold' my last Decca Navigator to a 'Yachtmaster' who brought it back because it wouldn't compensate for the tide..... gave him his money back in exasperation.

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Hi,
He has been sailing four seasons, before that dinghies.
As far as I know he does not transpose his position to charts.
The autohelm is not interfaced. However it is something of a standing joke that he runs aground frequently when using it. Also hit me in the stern!
He has promised his family he will not sail without an experienced crew, but he is running out.
I probably sound critical but I assure you I am concerned for him.
Regards Briani




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It seems daily someone on here is calling for compulsory licensing, which as I have no certificate to prove my worth afloat includes reckless skippers like me. Yet here is a skipper who should from what is said by some on these fora sail rings around me.

I hope to all the licence bill wavers on here this will stop you all from crying foul every time someone screws up or makes a mistake. Obviously compulsory training is not the answer.

I call a motion to stop thinking compulsory training is a good idea, anyone now tempted to write it should quietly stroll outside into their back garden and shoot themselves in the head, All say 'aye'.

<hr width=100% size=1>Julian

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I am sure that you have well based concerns, which are probably nothing to do with his use of GPS or autopilot but more to do with general seamanship!!! Perhaps a more tactful approach, like inviting him to sail with you and demonstrating a more controlled method (without being too obvious) might make him have a wee think in moments of quiet contemplation?

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>>I call a motion to stop thinking compulsory training is a good idea, anyone now tempted to write it should quietly stroll outside into their back garden and shoot themselves in the head<<

Of course, they would insist on compulsory training for shooting themselves in the head. If you're trained, its all OK, innit?

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GPS is in itself considered sufficiently infalable for aircraft here in Oz to let down through bad weather to a point around 500n ft above ground and 1km from where they must be able to see the runway end this using 1 GPS with self monitoring facility. If your friend has charts and can plot his position from GPS onto the chart then the GPS is sufficiently reliable to tell him where he is on that chart. Providing the GPS and power supply are reliable. So a hand held battery operated GPS may be worth while as a standby.
A passage plan is obviously necessary for all but a spin around the local area. Perhaps you are being too pedantic about navigation in criticising his approach. regards will

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It's a risk, and a bit difficult to quantify.

They do stop working believe me. I had fixed GPS and two hand helds as back up and plotted my position hourly, recording heading and log etc.
Then after one wet and windy 24hrs fixed GPS failed, I think someone grabbed the aerial on the stansion for support (note to move it) The connections at the base had failed, some corrosion and a bbreakage on inspection later. So out comes No1 hand held...3 hours later its got moisture inside, screen dies...second handheld...2-3 hours checking every half hour (I was a bit worried by now) in rain trying to keep it dry and it also fails due to moisture, lines start disapearing on screen.
No GPS and back to basics in shitty weather approaching a strange coastline in bad vis.
They do fail even so called water proof models....and the manufacturers weren't surprised, they were 2-3 years old.
Other electronic failures due to moisture...Eberspacher controller in Lazerette, auto helm relay, depth guage display on console (moisture under buttons), autohelm display on console, Volvo control panel audible alarm,

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Julian, the subject of compulsory training was not in my mind when I began this post. I have recently met two delivery skippers who admit they have no qualifications but clearly are well trusted. I believe, as others have said, that there is no substitute for experience. However I have to say I thoroughly enjoyed my course work and the practical even more. It seems to me that one goes on learning for ever. Also constant practice keeps the training in mind.
Regards Briani


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Jimi, I have to give you credit for spotting something I have only just worked out for myself. What you suggest would probably work for most people. Unfortunately as I sailed a season with him before aquiring my yacht, he would probably feel it was a case of pupil teaching the master. Even his wife admits he is pig-headed!

To give forumites an example. Last weekend he entered up waypoints into his new GPS. The passage involved a trip up the Swins and through the Spitway.Unfortunately he ommitted the Whittakers and Swin Spitway and sailed close to Foulness and over Buxey sands before rounding the Wallet Spitway.
All fortunately at high water. On the return leg he asserted he would sail a reciprocal course at low water.
I felt compelled to heave to off Foulness until I saw he was safe. As he met me, he assured me "It was fun"
Am I right to be concerned?
Regards Briani

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The GPS will allow him to follow a ground track between 2 wpts IF that is what he does, ie stays on track, no x-track error. However that presupposes the wpts he puts in are a) correct b) carefully selected to give a good straight line track to follow. He will be continuously adjusting course to compensate for the tide/leeway and stay on track or will have his pilot switched to 'Track' function, this may mean he is using his engine more since some course adjustments may not fit in with the wind direction. The method works well enough for short trips but especially over more than one tide will result in a longer distance travelled through the water as he will in effect be continuously stemming the tide, altering his heading continuously to do this. However on the plus side IF he stays on the groundtrack he will not be moved off line perhaps over shoals or rocks or whatever, whereas if say you compensate for overall tide effects and steer a constant heading your ground track could move left/right over areas of danger, you need to consider that possibility when planning.

Is that what you meant?

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on the plus side, yes, a GPS can allow for the tide etc. on my setup i hit 'goto' on the gps then 'track' on the pilot and i know the boat will follow the line on the chart with an error of no more than 100 ft, regardless of tides and leeway. i haven't plotted a course to steer in the last 15000 miles sailing, though i still know how to do it!

on the other hand i had a crew who plotted waypoints without looking what was on the track and would regularly try to route us over rocks, headlands etc.

so it's a good tool if used with care. i believe the prerequisites when relying on GPS are (a) know how to navigate without it, (b) keep a position log so you have something to work from if the GPS fails and (c) check your route and waypoints on the chart to make sure they make sense.

i also have found myself without instruments (as a result of water in a fuse box) and had to resort to a sextant to avoid the minkies.

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"He is convinced that the GPS will "automatically allow for leeway and tidal drift
and therefore he will not need to do his own calculations."
It does, and he doesnt. Provided he compares the track with the course to the waypoint, he is better off using the gps than messing around on the move with (at best) erratic leeway and inaccurate tide flows. Dont forget that the latter are only accurate for the places where buoys have been stationed. The figures in between in the atlas are guesstimates.

"1 If he persists he may run aground or strike an obstruction"
Only if he hasnt checked his charts / tide heights and not looked round him. Is this what you are really saying? Is he that casual? We all know someone who is an accident waiting to happen. At our club he's called Patrick - rescued twice this year so far. Nice chap.

"2 He is open to accusations of not having a proper passage plan"
So are most of us. What is "proper" in a passage plan will only ever be defined by non sailing lawyers after an accident. In the meantime, I dont think that the full "course to steer" calcs are necessary. Apart from anything else, you almost never end up at the start point at the time you originally expected so you have to do them again.
"3 He is already prone to relying on his autohelm, which coupled with
incorrect use of GPS, will result in disaster"
My boat is on autohelm 90% of the time it is out of port. Its safer, with me keeping watch rather than bored daft on the helm. I guess you mean he doesnt keep watch.

The statistics show that the sea is a lot safer place than most people think. Yes, he shouldnt be casual and sloppy - but many people are more frightened and worried than is warranted. By the sound of it, he will have to learn from experience and a good fright.


<hr width=100% size=1>this post is a personal opinion, and you should not base your actions on it.
 
Robin, thats the answer I was looking for. You see he is using a handheld and adjusting his course occasionally.
After earlier postings I was all set to apologise to him.
I suppose I should have given more information to begin with.
Trouble is I now feel a bit of a heel for publicly criticising a friend.
Regards Briani

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They sure do. Fixed Raymarine GPS failed to FIX after 2 years. Goes back to Raymarine who did not even seem that surprised. Good job for the 2nd fixed GPS Philips Navigator.

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As someone who relies almost totally on a GPS for navigation - I honestly can't remember the last time I looked at my compass - his presumption that it will compensate for tide drift etc. is quite correct; the GPS will always point him toward his destination BUT it's up to him or his auto helm to make the necessary course adjustments as conditions affect the true course. It's no use at all taking a bearing to a waypoint, setting the helm to that bearing and waiting to arrive unless he's on a lake. In addition, it makes sense to plot every journey on a chart giving any potential problems a wide berth and make copious notes on bearings, distances and safe havens in case the GPS ceases to function and to satisfy insurance requirements.

I have to agree with Jimi that it's a seamanship issue, not a GPS issue. Not knowing the area you are describing in this post, I assume he plotted a straight line as the shortest distance which, if I'm correct, is patently silly in this instance and not affected by his method of navigation. It was a foolhardy thing to, GPS or not.

All of which, of course, doesn't help you one bit with your predicament.

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Hi Briani
I see / hear about many such cases of simple over confidence. It's typical of any highly skilled and specialised sport which requires a full wallet but no qualification or training. If he's an accident waiting to happen, then happen it will, no matter how much he's nagged. If he's been warned by his friends and colleagues, then it's his fault alone, despite the hysterical and obsessive interference that has been bred by the Nanny State. I hope the rescue services aren't inconvenienced, injured or traumatised too badly when they pick up the pieces. Oh, by the way, our insurance premiums are ridiculously high because of people like this (if he's as bad as you say) - shouldn't you find out who he's insured with ................?

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