I decided to install OpenCPN and give it a try

[stephen_i_w]

The problem was even though I had down loaded all the O-Charts for the area I was interested in and I also did the "Prepare all ENC Charts" etc function and rebuilt the date base more than once etc. If one area's chart showed up, another blanked out. I could never get a continuous knitted visualization of the North Channel of Lake Huron at any zoom level. This made it difficult to chart routes etc.

This had never been the behavior of the NOAA ENC charts on Open CPN at all. With NOAA ENC charts I was always able to obtain continuous visualizations of areas I was interested in. Besides that, the detail level of the O-Charts is unsatisfactory. Both NOAA and Navionics charts are worlds better. I would not recommend O-Charts.

 

[Techstyle]

I have a Raspberry Pi 4B at the Navstation that has two HDMI outputs one to a 10.1" touchscreen at the helm and one to a 15.6" Waterproof, sunlight readable touchscreen at the helm. I run OpenCPN as my primary Chart plotter, although for long distance races I tend to use qtVlm because it is just easier for wind routing, once routed, I email a GPX file to the boat and load it in OpenCPN. I have seen some quilting issues but my experience has been that these tend to disappear when zoomed further in.

I created some Youtube Videos on my setup:

 

[SoSound]

Yes, I have everything from "Erie Harbor" up to "Great Lakes" loaded. Opencpn just seems to ignore them occasionally. Since I can manually pick one, it hasn't been too much of a problem.

OK... it has taken me a while to get to this point, but I think I understand what both @jssailem and @JBP-PA are saying.

@JBP-PA, are all of the charts that you have loaded RNC (raster) charts? And are your screenshots taken from an Android phone? It looks like the screenshot with Presque Isle and the bay are using a raster chart, and maybe at a level indicated by the highlighted tiles at the bottom of the screen. On your other screenshot, it looks like there is no active chart (nothing is highlighted), and what it is probably using is the base chart, and maybe a vector chart as @jssailem has suggested. Our Mac installations give us a scale on the zoom controls on the lower right, I can't tell what the zoom level or the chart scale is on your examples.

You have multiple charts downloaded, how proficient are you with managing storage on your Android device? The OpenCPN documentation that I skimmed through said that one of the most difficult tasks for Android users is managing the file system and the downloaded charts. I don't know anything about Android file systems, so once again, I will bow out of this part of the conversation... but, there are tabs in the Charts portion of the settings where I can see where all of my chart files are located. It even looks like I can verify that a specific chart is in that location by browsing the files within the Charts tabs.

 

[SoSound]

... The area in the middle is where I have not loaded charts. When the quilting function does not have a "layer" to display (at the zoom level) it resorts to display the Base chart provided.

View attachment 220712the Base

This is probably what is happening to me, there is a section within my window where the only chart that I have is 1:3,500,000.

When I zoom in and out, the detail for the San Juan Islands comes and goes, seemingly at random, I'm sure it's not. I think what is happening, is that I'm looking at a quilt of charts which includes the southeastern tip of Vancouver Island, and I don't have CHS or O-Charts for Canada downloaded. I can hover over the tiles at the bottom of the screen to see what specific charts are included in the quilt. My problem appears to be that at some point when I'm zooming out, I end up seeing a large portion of a very small scale chart (the entire top portion of the OpenCPN window). I can choose specific charts by clicking on the tiles at the bottom and get the detail back again, but this alters the zoom level within the window, and trying to recenter my route is where my perceived randomness occurs.

When poking around with it tonight, if the overall zoom level of the chart window goes out to greater than 1:300,000, then the smallest scale chart that I have overwrites the top portion of the window and the more detailed San Juans charts that I want to see.

 

[jssailem]

I experience the same behavior.
I think you can compound this issue if you have both the ENC Charts and Raster charts active. I feel it is best to choose one chart format.

 

[JBP-PA]

I experience the same behavior.
I think you can compound this issue if you have both the ENC Charts and Raster charts active. I feel it is best to choose one chart format.

I do have both RNC and ENC charts loaded. As @SoSound said it is an Android phone, the paid Dave Register version. For the screen shots I had "Raster" chosen though it also does this off I have "Vector" chosen. Sometimes when zooming out it reverts to the base chart despite having an appropriate chart loaded.

 

[jssailem]

It might be an issue to submit to the Cruiser Forum site as a glitch. They keep a record of all of those issues and work to resolve them.

 

[mermike]

I assign my NOAA ENC and RNC charts each to their own chart group. I also have my Canadian O-charts assigned to their own group. I select one group for display at a time.

 

[Stu Jackson]

It might be an issue to submit to the Cruiser Forum site as a glitch. They keep a record of all of those issues and work to resolve them.

John is right.
You guys can gaggle all you want here about OpenCPN, but you'll get yourselves in an endless loop.
Why not go directly to one of the sources? This is IN ADDITION to the link John provided on page 1, reply #11.

OpenCPN - Cruisers & Sailing Forums

OpenCPN - OpenCPN is a robust and free navigation software platform. Create concise charts, participate in development discussions, troubleshoot or get support help here.

www.cruisersforum.com

 

[SoSound]

For this particular issue, there does appear to be an adjustment in settings which will improve the chart quilting and display of charts. You want to change the Chart Zoom/Scale Weighting which can be found in Options: Display: Advanced.

I increased the weighting for Vector charts (+2), and decreased the weighting for the CM93 chart (-1). I didn't change any other options. There did seem to be a side affect to the change, it seemed to either reduce the mouse sensitivity for zooming, or to increase the processing required to build the display.

This screenshot shows both the Options panel and the affect on the chart where I was experiencing the problem before (problem area was San Juan Islands, east of Vancouver Island). Compare this to the first screenshot in this thread.

 

[jssailem]

Nice discovery Dave.

 

[kbgunn]

I wrote a post here about using a Dell ruggedized tablet PC running Ubuntu as a chart plotter at the helm.
Best Chart Plotter Solution

Still using this setup and like it. You can create your own charts using Navionics, C-Map, and Bing Maps with a tool called SAS Planet. It is a little involved and requires an investment in learning.

John Hacking posted a great tutorial on his website: Making mbTiles

He gives some tips on how to organize charts in memory which will lessen the conflict between ENC and RNC charts at various zoom levels.
KBG