Quality of CM93

[roger-jo]

Originally Posted by CarCode

You might use what you want but your example is misleading. Please do not confuse people. All Denmark charts are there but in different scales. In your example on the left it is C (scale 200000) and on the right it is E (scale 5000). May I suggest also to use the newer OpenCPN version instead of your outdated v4.8.0.

That's all there is no other map layer
Yes I use 4.8 never update in a boat season.

Are you saying that 4.8 cannot show maps west of 54 59.4516 N 011 50.4928 E from cm 93 "2015" but can show cm 93 2010

[Dockhead]

Originally Posted by roger-jo

. . . As others have written: the quality of the CM93 charting is variable, somewhere good, somewhere bad, and everywhere - out of date.
USE maps from https://o-charts.org/

Amen!






https://o-charts.org/


It has become easier and easier to get legitimate, licensed, up-to-date charts for OpenCPN at a reasonable cost.


I love CM93 charts as a base map, but it is pretty irresponsible to sail without up to date and licensed charts at least for the area where you are sailing. It is now much more affordable than it was 5 years ago so hardly any excuse not to.


Kudos to the O-Charts team.

[bcn]

The statement from C-Map about CM93/2 is that the series has been discontinued about 2009 and support ended.

They will not comment about modifications of the sets after the end of product live cycle and do not take any responsibility for this material. Ignored by C-Map.
Nothing else to debate about with fundaments.

Hubert

[Schnapsy]

Originally Posted by Dockhead

I love CM93 charts as a base map, but it is pretty irresponsible to sail without up to date and licensed charts at least for the area where you are sailing. It is now much more affordable than it was 5 years ago so hardly any excuse not to.

I agree.
As I wrote and illustrated in #8, the last recent cm93v2 cards are from 2014.

There are NO 2015 cm93v2 cards from Jeppesen.


And, of course, these cm93 cards are only for home.

To navigate, I use the OesENCs.

[roger-jo]

Originally Posted by CarCode

You might use what you want but your example is misleading. Please do not confuse people. All Denmark charts are there but in different scales. In your example on the left it is C (scale 200000) and on the right it is E (scale 5000). May I suggest also to use the newer OpenCPN version instead of your outdated v4.8.0.

Have you checked your CM93 "2015" map of Denmark

*Here is CM "2015" and OpenCPN 5.0 you see some improvement


nothing west of 54 59.4516 N 011 50.4928 E

[roger-jo]

Originally Posted by roger-jo

Have you checked your CM93 "2015" map of Denmark

*Here is CM "2015" and OpenCPN 5.0 you see some improvement

nothing west of 54 59.4516 N 011 50.4928 E

USE maps from https://o-charts.org/

[martinz]

Originally Posted by Simi 60

Navionics is notoriously incorrect in many parts of the world as we'll

http://www.cruisersforum.com/forums/...ml#post2500798

With regard to Navionics accuracy, instead of posting details of instances where it is inaccurate (in this case borrowed from someone else's post), has anyone ever thought of sending this information directly to Navionics and politely asking them to look into it. I've just done that - they have made the appropriate corrections, for the benefit of all users, and they may even do it (almost) while you wait. See attached fig 1 and 2
+1 for Navionics Customer Service.
Before you posted this, did you have a look at how CM93 V2 displays the same location, see fig 3.

The OP has expressed an interest in Vanuatu charts, where someone said "Mine works perfectly all through NZ, Vanuatu, everywhere."
Are people aware of this update:
https://dailypost.vu/news/vanuatu-ge...7ca3cf770.html

http://gisconference.gsd.spc.int/pre...vigational.pdf

I haven't been there yet, but when I do, I think I would want to be using a chart that incorporated the latest updates, in this case a full survey.
The CM93 V2 charts do not provide this. The CM93 V3 (aka C-Map) charts do, see attached fig 4 - Port Vila. I'm sure other chart providers do as well.

[Tupaia]

It would appear that there is a lot of misunderstanding surrounding vector charts and the OCPN settings for CM93 charts. This is the equivalent CM93-v2 dated 2006-10-24 of Port Vila.Port Vila CM93-2.JPG

Criticims should therefore be careful to compare apples with apples. Vector charts can be presented in more or less detail with more or less information. I am not suggesting the data is better or worse as has been stated earlier different charts will be more or less accurate / appropriate in some locations than others.

We navigated an entire season in Vanuatu using CM93 before the advent of OCPN and even with the best charts places like this require a great deal of looking over the bow with the sun high in the sky.

When we visited Indispensible Reef N12.66d E160.30d Google earth would have trumped any "charts" and the ability of OCPN to view both side by side would have been truley amazing but even with the most accurate "CMonics" chart I would still be looking over the bow.

[martinz]

Originally Posted by CassidyNZ

Unfortunately all the areas that do not form part of NZ’s protectorates (Cooks, Tonga, Samoa, etc) are not covered by LINZ charts. No Fiji, no New Caledonia, no French Polynesia, no Vanuatu. These are the primary cruising grounds for voyagers in NZ and LINZ do not cover any of them.

So charts for NZ, yes. Anywhere else of value, no.

I'll see if I can add some value to the OP's original specific needs, ie not Denmark or Philippines or Papua New Guinea.

Fiji, a notorious place to get good charting information:
I've been there twice, first time end of 2017. I got to see some of the dry side of Viti Levu - Yasawas, Mamanukas and around Denarau and Vuda Point. Attached is part of track taken by the Yasawa Flyer (big ferry) on its daily run through the Yasawas to the Blue Lagoon area dropping off and picking up punters along the way, dropping me off to a yacht for my return trip. This track was being created by SASPlanet with Satellite GE. At the time, Navionics was ok in most parts, but was lacking in some, eg Blue Lagoon area, compared to C-Map which was on the yacht's plotter on the return trip. Since then, Navionics have updated their charts and seem to be on a par with C-Map, at least in the areas I've visited. Attached is a small sample of the trip, chosen deliberately to show the Flyer crashing through an Island under CM93_V2 charts.
fig 5 GE via SASPlanet (also see CF posts on .mbtiles to use imagery with OpenCPN)
fig 6 CM93_V2 - note lack of detail and accuracy
fig 7 Navionics
fig 8 C-Map chart via SASPlanet
fig 9 CM93_V3 on MaxSea
CM93_V2 charts may get you into Suva harbor safely, but the level of detail deteriorates rapidly from there. Vuda Point, to the east of Treasure Island, favorite place for may cruisers to clear in/out, marina, bar, maintenance facilities incl. travel lift etc, doesn't even appear on the chart, however much you try to zoom in.

New Caledonia - going there in a few weeks so can let you know after that.

French Polynesia - Navionics worked for me in the areas I've been, see other posts in CF for more detail on FP

Vanuatu - see my previous post on this thread. Others may be able to provide more up to date information

I have only recently stumbled onto .mbtiles. This looks like a great way to use Satellite images and to experiment with (poor mans) C-MAP. I'll try this out "in the wild" in New Cal in a few weeks time.

I would recommend you retain your subscription to Navionics, always take satellite imagery of some sort that has GPS (SASPlant, Ovital, mbtiles in OpenCPN etc), maybe look at something else like C-Map or poor mans C-map or iSailor. iSailor seems to be favored by many people but has been getting hammered lately for their increased pricing model under their new owners.

[barnakiel]

I generally found CM93 lacking in areas that are not frequented by commercial or fishing fleets.


Not to say other brands are that much better.


b.

[Jim Cate]

On our last visit to Vanuatu, some 6 years ago, the CM93 charts of general areas were scanty in detail and poorly georeferenced. However, the inset charts of the bigger harbours were pretty good as far as hydro data, occasionally having disagreements with ATNs. However in this and many other island nations, one is a bit unwise if you depend upon ATNs, for they are not well maintained and often are missing misplaced or unlit.

The article from the Vanuatu paper extolling the new updated charts of the harbours is heartwarming, but not of a huge impact on yotties, since those chartlets were already pretty good.

And once away from commercial ports, eyeballs aloft and sat images are your friends!

Jim

[martinz]

Originally Posted by Tupaia

(1) It would appear that there is a lot of misunderstanding surrounding vector charts and the OCPN settings for CM93 charts. This is the equivalent CM93-v2 dated 2006-10-24 of Port Vila.Port Vila CM93-2.JPG

(2) Criticims should therefore be careful to compare apples with apples. Vector charts can be presented in more or less detail with more or less information. I am not suggesting the data is better or worse as has been stated earlier different charts will be more or less accurate / appropriate in some locations than others.

(3) We navigated an entire season in Vanuatu using CM93 before the advent of OCPN and even with the best charts places like this require a great deal of looking over the bow with the sun high in the sky.

(4) When we visited Indispensible Reef N12.66d E160.30d Google earth would have trumped any "charts" and the ability of OCPN to view both side by side would have been truley amazing but even with the most accurate "CMonics" chart I would still be looking over the bow.

(1) I think you have missed my point, Vila harbor was re-surveyed in 2014. Any updates as a result of this will not and will never be reflected in CM93_V2 charts. No amount of zoomining in/out or detail hiding/unhiding will incorporate the updates provided by the 2014 survey.

(2) Help me out on this one, to compare apples with apples.
Lets say you visit an area the OP has requested specific information on like Fiji.
What would you have on your OpenCPN dual screen if you were following the Yasawa Flyer (ferry) track to check out "Treasure Island", here is a link to the track:
https://www.dropbox.com/s/kq230ppb4a...Flyer.gpx?dl=0
If I was there, I would have Satellite image on one side, CM93_V3 aka C-Map on the other, like on the attached screen shot, but with the CM93_2 side replaced with GE Satellite. Also if using CM93_v2, which version would you use? I can't find a version that shows any detail or accuracy for this area. A screenshot of your solution would be good.

(3 & 4) I agree

[Tupaia]

Specific area looks fine. Checked the whole route and looks OK

It looks like there are several sets of CM93 charts knocking about that are not all good. Some further investigation maybe.

http://www.cruisersforum.com/forums/...1&d=1568359640

[Simi 60]

Originally Posted by martinz

.

The OP has expressed an interest in Vanuatu charts, where someone said "Mine works perfectly all through NZ, Vanuatu, everywhere."
.

You are being rather disingenuous in saying this.

The op was having issues with how the charts displayed.
When I said mine work perfectly that was in relation to how they displayed, not their accuracy.
Having cruised through vanuatu, I am fully aware the are not accurate, neither are my C-map charts or navionics and I daresay any other chart set.

. With regard to Navionics accuracy, instead of posting details of instances where it is inaccurate (in this case borrowed from someone else's post), has anyone ever thought of sending this information directly to Navionics and politely asking them to look into it. I've just done that - they have made the appropriate corrections, for the benefit of all users, and they may even do it (almost) while you wait. See attached fig 1 and 2
+1 for Navionics Customer Service.
Before you posted this, did you have a look at how CM93 V2 displays the same location, see fig 3.

The op then said he would be using navionics and that was when I showed the picture, with link crediting to someone else, showing that navionics is inaccurate as well.

[Tupaia]

Originally Posted by martinz

If I was there, I would have Satellite image on one side, CM93_V3 aka C-Map on the other, like on the attached screen shot, but with the CM93_2 side replaced with GE Satellite. Also if using CM93_v2, which version would you use? I can't find a version that shows any detail or accuracy for this area.

To my knowledge OCPN is unable to use vector CM93_V3 (aka C-Map) as they are encrypted.

The screen shot was from CM93_V2 - 2006-10-24.