Forums > Sailing General

Open CPN continued

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Created by Andrew68 5 months ago, 30 Jul 2024
Andrew68
VIC, 428 posts
30 Jul 2024 2:18PM
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Following from the OpenCPN thread last year.

In anticipation of official paper maps finally dying, I finally started getting into Open CPN. It was a steep learning curve with lots of steps, but after a long night spending 12Euro at O-Charts and $80AUD at Boat Books, I managed to down load my 1 years licence of official ENC S63 charts from Gladstone to Port Macquarie. The only mistake I know I made was linking my home laptop, when I should have links the boats . I don't think I can transfer the permit unless I got the dongle.

In addition to the detailed charts you also get some of the large scale charts including Lord Howe, as far south as Macquarie Island and to PNG in the north. Here is Mooloolaba showing the leads:



and the official AIS leads on the Bar which I dont think are on the paper charts (but are on Navionics)


Cant wait to hook it up to the instruments.

Trek
NSW, 1160 posts
30 Jul 2024 5:18PM
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Its great, I use it all the time on a Notebook PC. All the new model Trek Transponders have a streaming NMEA0183 GPS data output especially for it.

JonE
VIC, 311 posts
30 Jul 2024 6:46PM
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Andrew - you're all good I think - from the website: o-charts | Charts for OpenCPN

oeSENC and oeRNC charts can only be used in OpenCPN.The license of a chart entitles to assign and install it on more than one device running Windows, Linux, macOS, or Android Operating Systems. The most common case is two assignments per license. You can use them simultaneously or you can save a backup to use in case your main device dies.


Lads, top tip...

Paste your waypoints into chatgpt (in my case straight out of the sailing instrructions from my club) and ask it to create a gpx file for you.

Save the xml in notepad as a text file (but with .gpx suffix ideally) and open it up from OpenCPN.

This will just suck all your waypoints straight in. You can give them different icons, group them together etc.

I ended up using OpenCPN to print out a "custom" chart with all the club marks on it which I took to OfficeWorks and got laminated.

Kinora
VIC, 177 posts
31 Jul 2024 2:43PM
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Can confirm that the same O-chart subscription will work on 2 devices. I have the same subscription on a Galaxy tablet and a Raspberry Pi. Check any destination for detail, though. I recently discovered that the latest charts only covered the Gippsland Lakes east of Fraser Island. cammd on the forum found a similar thing for north of Crab Island in QLD. We've both contacted O-charts but for me at least, the problem isn't resolved.

K.

Quixotic
ACT, 106 posts
31 Jul 2024 3:34PM
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I think it is a problem of lack of source material, rather than O-charts omission. Based on the Australian Chart Index from the Australian Hydrographic Office (see services.hydro.gov.au/AHOChartIndex/), the AHO doesn't produce a detailed (large scale) electronic chart for the area of the Gippsland Lakes, west of Fraser Island. If the AHO doesn't produce a chart, where would O-charts get the necessary chart? I note the zone of confidence for the area west of Fraser Island is D.

Screenshot from ACI

Kinora
VIC, 177 posts
1 Aug 2024 8:14AM
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Thanks for clarifying, Quixotic. My memory may be misleading me but I seem to recall OpenCPN had detail west of Fraser Island in an earlier version about 4 years ago. Maybe AHO dropped it due to reliability?

K.

Quixotic
ACT, 106 posts
1 Aug 2024 10:59AM
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Have to ask AHO I think. They produce two ENCs that jointly cover the area - AU438147 and Au439147. Plus the ENC that gives much more detail of Fraser Island and to the East - AU5LEN01 (presumably Lakes Entrance North 01), but no more detailed ENC for the rest.

So I suppose the question is what detail is contained in the first two ENC.

I had a look at the area on the ACI app that displays the chart index see the screenshot below which shows a bit more detail than o-charts:

I also had a look at the C-Map charts that are used by my B&G plotter (shown in screenshots below) which shows a lot more detail. Unclear where C-maps would get this other than AHO (though they mention Gippsland Ports Committee of Management Inc in their notes - see below), so maybe it is present in the AHO data. If so would take you back to the theory that it is O-maps processing rather than AHO ENC limitation.

There is still the issue of zone of confidence (maybe the C-Maps detail on depth contours cannot be trusted.)

I understand C Maps has a social mapping input where people upload their depth soundings and GPS data, but I've got no idea if that is relevant here. And the C-Maps notices (disclaimer) is a pearler - see text below




Text of C-MAP notice

Updated: 20 December 2023

No National Hydrographic Office has verified the information in this product and none accept liability for the accuracy of reproduction or any modification made thereafter. No National Hydrographic Office warrants that this product satisfies national or international regulations regarding the use of appropriate products for navigation.

The electronic chart is an aid to navigation designed to facilitate the use of authorised government charts, not to replace them. Only official government charts and notices to mariners contain all information needed for safety of navigation and, as always, the captain is responsible for their proper use.

New charts and/or NTM corrections will render this product obsolete and inaccurate. Updates may be available from C-MAP, but always remember that these electronic charts are inadequate as a primary means for navigation and should be used only as supplement to official government charts and traditional navigation methods, unless otherwise specified by national marine authorities.

Australia
The Australian Hydrographic Office and Gippsland Ports Committee of Management Inc. do not check the information in this product and the Commonwealth and Gippsland Ports Committee Management Inc. accept no liability for the accuracy of copying of their material or for any modifications that may have been made to the information which has been supplied.

Furthermore, the Commonwealth, the Crown in Right of the State of Victoria and Gippsland Ports Committee of Management Inc. do not warrant that this product meets any regulations as an appropriate product for navigation or that it contains the latest hydrographic information available.

The data has been used in the product with the permission of the Commonwealth and Gippsland Ports Committee of Management Inc. The Commonwealth and Gippsland Ports Committee of Management Inc. have not evaluated the Data as altered and incorporated within the product, and therefore give no warranty regarding its accuracy, completeness, currency or suitability for any particular purpose.

Based on, or contains data provided by the State of Queensland (Department of National Parks, Recreation, Sport and Racing) and Gippsland Ports Committee of Management Inc. In consideration of the State of Queensland, Gippsland Ports Committee of Management Inc. permitting use of this data you acknowledge and agree that the State of Queensland, the Crown in Right of the State of Victoria and Gippsland Ports Committee of Management Inc., or its Directors or employees, give no warranty in relation to the data (including currency, accuracy, reliability, completeness, or suitability) and accepts no liability (including without limitation, liability in negligence) for any loss, damage or cost (including consequential damage) relating to any use of or reliance on the data.

Quixotic
ACT, 106 posts
1 Aug 2024 11:16AM
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Speaking of the Gippsland Ports Committee of Management Inc, they produce some cracking depth charts for Gippsland Lakes and other Eastern Victorian waterways - check out www.gippslandports.vic.gov.au/wp-content/uploads/2024/07/gl6801-mga2020-20240701-vicinity-of-the-inner-entrance.pdf The survey was done on 1 July this year and checked on 8 July, and the zone of confidence is A1 - as good as it gets. And they've another of the Lakes Entrance bar and entrance done on 9 July this year. To check them all out, go to www.gippslandports.vic.gov.au/publications/bathymetric-surveys/

edit: I should add that they're using the Australian Height Datum (AHD) - 0.757m as their chart datum. AHD is essentially mean sea level averaged across 30 tidal gauges around Australia back in 1966 - 1968 (except for Tas which was rebased in 1983 on 2 gauges' readings in 1972). I haven't gone looking to see how AHD - 0.757m corresponds to LAT - the most common datum for depths in Aust marine charts.

Ramona
NSW, 7633 posts
1 Aug 2024 6:11PM
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That chart has the lat and long on it so you could use that to make charts for use in Seaclear. Run Seaclear alongside OpenCPN and make highly detailed charts any size you like. I use OpenCPN now but when I was a fisherman I used Seaclear and maps made from sections of AUS 808, some of them 0.5nm across as work charts.
In NSW the charts from Waterways are very accurate. They have lat and long so they can be easily annotated and made any size. They unfortunately have safety messages on them.
www.nsw.gov.au/driving-boating-and-transport/using-waterways-boating-and-transport-information/navigation-communication-maps-times-and-restrictions/boating-maps#toc-south-coast-maps



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"Open CPN continued" started by Andrew68