Charts are horrible quality in OpenCPN vs Browser

[irregularpineap]

Hello,

In the browser the charts look OK ( https://i.imgur.com/AKoTuj8.png ), even in the chart download helper ( https://i.imgur.com/s4yyY7P.png )

After downloading the KAP files and then inserting them into OpenCPN -- the charts are absolutely horrible.

opencpn: https://i.imgur.com/KuUCg3K.png

The max zoom in openCPN is absolutely disgusting and unusable. What is going on here?

OpenCPN settings: https://i.imgur.com/evq94lU.png

[nohal]

Originally Posted by talmobi

What is going on here?

The "charts" you are using are crap, nothing to do with OpenCPN.

[RaymondR]

You need to be careful criticising OpenCPN around here, a lot of us love that program.

I have two MFDs with different chart systems in them and I wish one of them would work as well as OpenCPN.

[fgd3]

Nohal is right. OpenSeaMap charts are crowd sourced charts which do not include water depths. While interesting to look at they are not suitable for navigation.

[nohal]

Originally Posted by fgd3

Nohal is right. OpenSeaMap charts are crowd sourced charts which do not include water depths. While interesting to look at they are not suitable for navigation.

That they are useless is the other problem with them, I was refering to the quality of the KAPs they produce in my response though.

[Bill O]

Originally Posted by nohal

The "charts" you are using are crap, nothing to do with OpenCPN.

100% agree.

We have a full range of chart quality due to some areas that are not well surveyed. Some that are not that good to ones that are excellent. Need to find the better charts.
Looked at the OpenSeaMap charts, but didn't continue to download them because they were poor quality.

[irregularpineap]

I had to create new account because I can't reply with the other account due to error "suspicious activity".

The problem is that OpenSeaMaps chart is looking fine when I view from browser -- it is very detailed -- but when I download and add them to OpenCPN it looks very bad and there is no detail at all.

How can I download OpenSeaMaps charts to OpenCPN so I can look at them offline?

Thanks

[nohal]

Originally Posted by irregularpineap

How can I download OpenSeaMaps charts to OpenCPN so I can look at them offline?

As you have already found out yourself, KAPs are extremely unsuitable for conversion from tile data, especially without investing a lot of effort and thought into what is being done, MBTiles are a much more suitable format for this task as it's logic is virtually the same as the tileserver's and due to the technical aspects of it, much more imagery can be stored in dataset of the same size.

If you are not happy with MBTiles OSM make available themselves at https://downloadlayer--onlinechart-o...s=A1-1&lang=de , you may still generate MBTiles with parameters and coverage that suits your needs from the OSM data yourself using tools such as SASPlanet and SAT2Chart.

But be aware: That everybody tells you OpenSeaMap is useless as navigation chart has a reason. That reason is it is useless as a navigation chart.

Being you I would probably consider saving myself the disappointment and time wasted and acquired real nautical charts as the area of your interest seems to be well covered by https://o-charts.org

[bcn]

The zone you were looking at in the Swedish o-charts set - the data are identical to those of the official Swedish ENCs as we source them from the Swedish authorities.
You will see some more information for navigation you might be interested to know about.

[SeanPatrick]

Originally Posted by talmobi

Hello...

Hi. I just saw the message you sent me. Did you get the problem resolved?
If not, you should contact a moderator and ask them for help.

[irregularpineap]

Thanks all. I'm using Navionics instead it works well for my needs and easy to use.

I will just have raspberry track/log position of boat that I can use for whatever later.

[RaymondR]

Originally Posted by RaymondR

You need to be careful criticising OpenCPN around here, a lot of us love that program.

I have two MFDs with different chart systems in them and I wish one of them would work as well as OpenCPN.

Further to the above:

I used OpenCPN and CM93 for about ten years to navigate around the coast of Australia which included a 3,000 nm cruise from the east to the west coasts across the north of the continent.

It was an excellent choice of navigational planning and course control being readily used on a number of small computers along with cheap USB GPS pucks, AIS receivers and a Raymarine ST4000 autopilot. The NMEA0183 multiplexing functions written into the program are simple to implement and work reliably (however one does need to be careful with the Microsoft software and I found it most reliable on a dedicated 10" Asus computer with no other software on it)

Even though I upgraded (from a shiny gadget viewpoint) my nav spread on the boat I now use I have retained OpenCPN and the CM93 charts on a tablet which I use for passage planning and to overnight monitor vessel position when anchored.

I use the ANCHOR WATCH function in a waypoint placed when I anchor if I am at all concerned about the anchor holding. After placing the waypoint and setting the anchor watch on it I turn the screen off and take the tablet to my bunk. If the vessel vacates the watch circle the alarm alerts me and I can respond accordingly. I cannot do this with either of the MFDs as they are fixed at the helm position.

So, even though I have indulged myself with a plethora of new navigation gadgets and two expensive chart cards to steer the boat and keep me off the rocks, trusty old OpenCPN still serves me well in allowing me to rest peacefully and largely undisturbed when anchored at night.

[irregularpineap]

It's all well and good that there is praise for OpenCPN, but it doesn't really answer the original question.

Why can't the OpenSeaMap maps be imported correctly to OpenCPN? I mean they even provide links for downloading, but the maps they give are crap and not the same that are hosted on OpenSeaMap?? Why??

And if OpenSeaMap is showing maps on their browser viewer that is not part of OpenSeaMaps, but instead behind a pay wall -- then why don't they inform of this and what is the point of OpenSeaMap at all? It's not very "open" at all, is it?

Frankly it doesn't make sense and it's stupid.

[bdbcat]

talmobi...


I find the the OpenSeaMaps KAP compilations can be imported and used in OpenCPN with no problem.
The trick is this: Due to the "strange" scale values used for the KAP charts in a compilation, it is best to boost the OpenCPN RasterChartScaleFactor to see increased detail at a specific screen display scale..


Options->Display->Advanced->Zoom/Scale Weight
The results are attached as screenshots, near Wolgast in northern Germany.


Make your own judgement whether to use these charts for navigation....


Good Luck
Dave

[hoolie]

I have OpenSeaMap charts installed on my laptop and they work perfectly well with OpenCPN. I don't use them for navigation but they are useful for showing road layouts and other coastal features of places we visit, information that's much more detailed than marine charts.