Dutch01527
Well-Known Member
I remember RDF, it was a pain to get an accurate position and no use offshore. We also used to have Decca and Loran which where no better. Over 50 miles away from the coast and it was celestial sights or nothing.
Navigating without a log
- Thread starter Graham_Wright
- Start date
I remember RDF, it was a pain to get an accurate position and no use offshore. We also used to have Decca and Loran which where no better. Over 50 miles away from the coast and it was celestial sights or nothing.
lw395
Well-Known Member
Apart from Decca, Loran, transit satnav, Lanbys, Racons, RDF, gyrocompasses, depth sounders with more than 20 fathoms of string and one or two other 20th century innovations?
RupertW
Well-Known Member
And DR of course which got us across the Channel and Western Aproaches many times (often in mist)
johnalison
Well-Known Member
You didn't have to go offshore to get lost. Just crossing the Thames Estuary meant that you had to go close to every buoy just to read the name or number. My one triumph was in making a passage from Boulogne to Dieppe in the fog, some 55 miles, with a nervous fellow club member following. I was relieved when the offing buoy appeared dead ahead and was pretty successful in pretending that this was the result of skill.
john_morris_uk
Well-Known Member
Decca has only been about a few years and is no good more than a hundred miles or so offshore.
Loran ditto and has limited coverage.
Transit Satnav only became available in the 70's.
RDF only works within range of short transmitters and therefore close to shore.
Gyrocompass - so what?
Depth sounders - again so what (even if they read what to several thousand meters depth it doesn't tell you where you are..)
The discussion had moved on to navigating out of sight of land across oceans. None of the above are very much help with ocean nav so I don't know what point you are making.
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lw395
Well-Known Member
The point is, a lot changed in the pre-GPS era.
Decca, Loran, RDF go back to the war, even if not everyone had them.
Transit goes back to the 60s? But was only for the big boys?
For sure many of these aids only worked relatively close to landfall, but presumably made a big difference between a DR landfall being good enough and not?
Plus AIUI, gyros and autopilot made a big difference to the accuracy of DR, compared to manual steering?
Dutch01527
Well-Known Member
In 6 years in the British Merchant Navy (1970’s and 80’s) and c.100,000 miles of meandering around the world we never used anything other than celestial navigation and DR when not close to land.
oldmanofthehills
Well-Known Member
I would like my log to work so I can see how my trim is working or how my water speed compares with gps speed in tidal areas as I try and cheat the current in the bays. Sadly my hull based logs all clogs both the paddle wheel and the screw. However my slow boat does about 4kt and we managed fine in fog from Milford to Cardiff and also Camaret to Plymouth without a log. Navigator did stress about unreliable gps plotter and we marked it all on paper at regular intervals but I pointed out that there was little to hit if we stayed on course and we would see things well before we hit them and would know fairly well when that might be, so primitive dead reckoning would cover any electronics failure. Mind you I wouldn't do it without a compass ever.
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I did Brest to A Coruña and while leaving the rade the log packed in, it returned on day two.
How many would turn back in the face of a good forecast with normal GPS gear for the sake of the log?
How many would turn back in the face of a good forecast with normal GPS gear for the sake of the log?
john_morris_uk
Well-Known Member
If I was a day or more out I wouldn’t turn back if I had no GPS or Log.
But I always carry a sextant and a walker log and even if I lost the spinner and the spare you can always make a chip log or estimate your speed and distance run.
I’d get anxious without an echo sounder though. (Even though we carry a lead line)
RupertW
Well-Known Member
I don’t carry a sextant but would still keep going on a Biscay passage without. GPS or log, but not an ocean crossing. Once you’ve crossed the channel at the wide end a few times by DR with fog in parts then you get used to the old technique of estimating your speed and building in an offset based on your likely error so that when you finally see a new unidentifiable coastline you know to turn left or right until your destination appears.
I love GPS but we’ve never had a chart plotter and mostly sail by line of sight. Where that’s not possible then a GPS position on the chart every 3 to 6 hours works fine for us.
john_morris_uk
Well-Known Member
I agree - more or less.
I'd be glad I had a sextant for Biscay because after a few days (which it can easily take) your DR starts to get a bit iffy...
I too have crossed wide parts of the channel on DR. (eg Penzance to L'Aberwrach). Fog as you approach that bit of Brittany concentrates the navigators mind wonderfully. I suspect that those of us who remember doing such things are becoming fewer in number.
TamarMike
Well-Known Member
When Salcombe had dredging done in the 1980s the contractor had to get 2 tugs there from Plymouth The first seagoing tug duly arrived in not too good visibility and its professional skipper was surprised when the proprietor of the firm arrived with the second small river tug in the early hours of the morning despite having no navigation aids at all. Apparently the shipping forecast said westerly winds so they'd 'followed the smoke from the funnel'!
RupertW
Well-Known Member
I am increasingly aware that my internal view of myself as the twenty something modern young sailor in Concarneau in a 24 footer is a odds with my view in the mirror. I thought about a sextant (and learning how to use one) on our 5 day Rabat to Lanzarote a few weeks ago as it was overcast the whole time with just occasional brief glimpses of where the sun was.
obmij
Well-Known Member
Assuming this is a commercial vessel please refer him to the Workboat Code(code of proactive for the safety of small workboats & pilot boats) and also MGN 280 - but to be honest if he is a commercial skipper he should know these two publications back to front anyway.
Sounds like he is working for a cowboy operation. If the compass is goosed, how are the life-rafts, bilge pumps, FFA etc?
Graham_Wright
Well-Known Member
He has arrived at that decision also! It was a one off trip and he has declined the offer of further work. It was still his responsibility though.
john_morris_uk
Well-Known Member
Indeed - see my post No25 in this thread - although I was at sea and couldn't remember the correct names for the codes of practice etc.
I'm delighted that the young man has foregone any more work with the company involved. Any accidents or incidents and it falls on the head of the skipper as well as the management company...
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Ahem...
(Workboat code says the same, being based on 280)MGN280 said:
So GPS is actually acceptable, I think we would all agree that most sets provide "reliable distance measurements", at least compared to other types of log.
I also think the trip described could actually be done in cat 2 waters. Thus not requiring a log at all. Makes sense if you imagine a water taxi or small ferry which is little more than a big dinghy is hardly going to be dead-reckoning its way around.
Not that it's a great idea, and the boat does sound a bit knackered.
obmij
Well-Known Member
Agreed - but a compass is essential (which was obscured)
It's pretty tough declining anything when you are starting out as a skipper so good on him for doing so if he thought that was the best course of action. It's difficult striking a balance between managing & progressing defects (which every vessel has) and putting up with unacceptable safety issues. It's the hardest part of the job. Hope he has every success in finding further work.
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They must have had a hand compass though, you don't have to have one fixed to a bulkhead. The actual practice matters more than the polish.