Adios
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Yeah its funny with the moon. We don't realise we're noticing its orientation until we go somewhere else and its hung up wrong
Does anyone still sail without a chart plotter?
- Thread starter Adios
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Adios
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Whats that?
Bobc
Well-known member
Yes, you can get AIS data, tidal stream direction and speed, tidal heights (even at secondary ports), you can overlay your radar (with AIS also showing). It's quite incredible to be honest, and it does make for a much less stressful passage having all that information at your fingertips and also being able to see exactly where you are on a chart all the time, without having to go and plot it to find out.
When I first got the plotter, I still did all my nav the old way and just used the plotter as a sanity check. I now use the plotter as my prime source of information, and plot hourly fixes when on passage, just as a sanity check and a backup. Thing is, even if the plotter goes down, I still have Navionics on an iPad and on my phone, and a GPS position app on my phone, so the only time I'd really be stuck to going back to DR or following depth countours is if the entire GPS system goes off-line.
Never Grumble
Well-known member
How do you know it hasn't changed if it hasn't been surveyed for sometime. I suspect it hasn't been updated because it is not of commercial or military value.
The Isles of Scilly are a very good example ... I only have the chart for Lands End to the Isles of Scilly here, on this it is annotate to show the data for the charts as coming from British Government Surveys (leadline) 1851 to 1898 and other parts are British Government Surveys 1965 to 1977. Therefore, It doesn't matter how good your plotter is. I don't have a chart for Chichester harbour here, but in terms of source that is also dated, have any of the mud/sand banks moved since ... probably but no one knows for certain.
Interesting having had a look the admiralty Leisure Series don't include the source of data so perhaps I should forget my big ship knowledge and worry more about trimming my sails properly.
If anyone can show me where to find this source data on Navionics I'd be eternally grateful.
Bobc
Well-known member
I have both Navionics vector charts AND Imray raster charts on my plotter, and I actually prefer using the Imray raster charts as they make more sense to me (I guess that it's just what I'm used to seeing). The colours on the Navionics charts always seem the wrong way round to me (deep water is white and it goes darker blue as it gets shallower), and it just feels a bit, well, Mickey Mouse. I do like the Navionics information though (tidal data etc.).
Adios
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Quite possible but a lot of stuff just doesn't move, but if it does to a point where its noticeable it would be reported?
I would assume they were quite handy with a leadline by the time they got to the Scillys. I wouldn't trust one of todays youth on minimum wage to not be distracted by his phone but in the 1850s there was probably more discipline and pride in their work.
And if it is right enough that its not been questioned in 170 years it is probably right.
davethedog
Active member
We are here in the Canraies, and have Navioncs charts for the Raymarine Axiom Pro plotter and also for tablets etc and very accurate.
Also have oesenc charts for the OPENCPN and they are very good also, but I would say that the Navionics is better as more updates.
A note ref the CM93 charts people may have, here they are very out of date, for example here is the CM93 for outside Puerto de Mogan vs the oesenc charts and you can see the fact that the yellow buoy/restricted area is NOT marked on the CM93 charts but is on the oesenc charts.
Also shows on the Navionics charts.
Attachments
newtothis
Well-known member
Vasco de Gama was a trained navigator and I bet he would have used a chartplotter were it available. Do you think he turned his nose up at these new-fangled astrolabes just to prove he could still use a cross-staff?
doug748
Well-known member
Courtesy RH Marine
I want one of these, but I put up with a 5in plotter for tricky bits. Plus ancient charts for what the liberal minded might call my "planning".
.
Uricanejack
Well-known member
Thanks
interesting differences in the charts display. apparently all giving accurate position relative to the marina.
My question was rather short and not very clear.
Its been something over 30 years since I passed by, what I recall from the admiralty charts, the positions of the islands didn’t match up. with the other islands.
So when passing between you only took positions of of one island not both.
if you were near a particular island the rocks ect were referenced on the island, so the fact the islands position was a bit off didn’t matter,
I was wondering if Mordor Electronic charts which didn’t exist or I had never seen. Have the Islands positions updated.
The old admiralty chart probably unchanged. Though updated.
I asked about the Canaries as a particular area I recall the discrepancy being quite noticeable and popular with today’s sailors.
If electronic charts have been updated to correctly position the islands, this would be an advantage over printed.
Adios
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It would do though in that example. Get you to the right place and the buoyage is intended to be used as a visual aid in its own right. That said I nearly got inside the buoys marking the Montgomery wreck in the Thames one night. They are that far apart that I got confused when I was up close, though worked it out in the end. Being as its clearly marked on a chart I should have been on a plotted a course well clear but I was freestyling it at the time.
Other than completely new harbours and wrecks not being marked on it i'd bet it would do fine in nearly every situation. Knowing its out of data if anything would make me more cautious and keep a better watch which I should do anyway. As the other poster said and I think i'm the same more kept as a back up.
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Buck Turgidson
Well-known member
I use Imray paper and Imray on my iPad It just makes sense.
I keep a log every 4 or 6 hours depending on the trip but the only time I put x on the chart is when I want a record for posterity, last time was on my 1600nm single hander to the Med. It was the same plotting chart I used 6 years earlier to go from the Algarve to Azores! (It's my epic trip chart).
prv
Well-known member
Wishful thinking. Last time I was in the Channel Islands, we nearly had a very nasty grounding (escaped with inches under the keel on a fast-falling tide) on a drying sandbar that had grown across the northern exit from the Maitresse Ile anchorage. Completely uncharted, and I'd updated the Navionics card and applied Admiralty corrections to the paper folio a couple of weeks previously in anticipation of the trip. We later heard from a local that it had been there for years.
Pete
prv
Well-known member
Both products are generated from the same hydrographic database. An old paper chart may be wrong where a new electronic one is right, but that's a function of age rather than format.
Pete
prv
Well-known member
I too like the Imray presentation, but it's funny that you'd describe the traditional, official, Admiralty and internationally-standardised colour scheme as the "Mickey Mouse" one ?
Pete
lustyd
Well-known member
My B&G lets me choose the colour scheme, is that not standard?
saab96
Active member
I started sailing when handbearing compass and echosounder was all there was. Bought RDF (remember that? Useless) to cross the North Sea. Thought Satnav wonderful when I sailed Essex to Scandinavia. Used sextant and GPS when I sailed to Caribbean. Only fitted a chart plotter a few years ago. It’s fantastic. I discovered with GPS that the smaller the boat you sail and the more often you single hand and cruise the coast the more you benefit from quick and accurate positioning. The chart plotter takes you to a new league. It was helpful when I singlehanded from Portugal to the Azores (marking my position on paper, of course) but it was life saving fighting the tide to get into the river off Faro on a dark and blustery night when the last thing I needed in my hand was a paper chart. Just get a plotter. You won't regret it whatever kind of sailing you do.
Adios
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Interesting post from 2017 claiming the CM93 charts are still accurate enough but that they're not so good on a tablet. OpenCPN w/CM93 charts on a tablet - Cruisers & Sailing Forums (cruisersforum.com)
There's no way to use this data on a typical small installed in the cockpit plotter?
There's no way to use this data on a typical small installed in the cockpit plotter?
Laminar Flow
Well-known member
To only use a sounder to determine water depth for anchoring purposes is to disregard the very much greater part of it's usefulness as a navigational tool.
It only goes to show how much common sense and basic understanding of where you are and how to go from there to the place you are heading to has been superseded by the video game convenience of blindly following that little avatar across the screen.
jimi
Well-known member
I did have a quiet chuckle at the thought of chart depths being more useful than a depth sounder for collision avoidance. IMHO a depth charger would be even more useful for scaring off submarines.;-)