How to hide pink circles

[MazatlanMexico]

Hi;
I think is a good feature to have at all times except when one is navigating on high seas. How do I go about hiding all of the pink circles with a cross on the charts? See screenshot here:
https://login.filesanywhere.com/fs/v...8a60676fad9ca4

[bcn]

You know what the symbol is about?



The OpenCPN manual is your friend:
https://opencpn.org/wiki/dokuwiki/do...nger_symbology

[Hakan]

I suppose you're pointing to a "isolated danger" in this case a wreck?
They are shown like that if it's depth is less than your "safety depth". See more here:

https://opencpn.org/wiki/dokuwiki/do...nd_deep_depths


And why not start to earn more knowledge about vector charts as such here:
https://opencpn.org/wiki/dokuwiki/do...or_display_tab

[MazatlanMexico]

If I double click on it a box pops up and describes it as an under water rock. As I said, this is helpful if I am navigating inland but I would like to know how it can be hidden when navigating on the pacific ocean. Just curious if there is a way to turn that off. I will read the manual to see what I can find about it. Can someone here give a hint about which section of the manual refers to this pink circle? Thanks

[MazatlanMexico]

I apologize. I had not seen the links from your replies when I posted my reply. It looks like it has something to do with depths. I will play with it to see if I am able to figure it out.

[Hakan]

Yes, we have three setting for depths. They can be used in different ways but my boat (1.7 meters depth) and own philosophy gives this:

- Shallow: 2 meters > Dark blue: keep out.
- Deep: 3 meters Light blue; be careful. > Deeper water is white and safe.
- Safety Depth: 5 meters to get highlighted soundings where I should not anchor due to weed/grass and to get rid of unimportant isolated dangers.

[requiem]

Originally Posted by MazatlanMexico

It looks like it has something to do with depths.

Indeed! As Hakan indicated, the isolated danger indicators are shown or hid based on the safety depth/contour setting.

The traditional approach is to set the shallow contour to the "will run aground" depth, while the safety contour is calculated from your draft, safety margin, and height of tide. The deep water setting is then used however one likes, e.g. to mark areas shallow enough to anchor in.

Since the contours defined in the charts can be deeper than the value you select (the computer rounds up), it's possible that you sometimes will need to cross the safety contour. That's why soundings shallower than the value you enter will appear in black font, to make the hazardous ones more visible.

Thus, the simplest way to make the isolated danger marks disappear is to adjust the safety depth/contour to be deep enough. You may wish to do this anyway, for example what I consider a safe depth within a bay is different from what I may consider at sea. The Potato Patch Shoal outside SF may be 7-9 meters deep, but that doesn't mean I consider it safe water.

[bcn]

When using ENCs one shall have the NOAA chart1 document as a reference at hand:
https://nauticalcharts.noaa.gov/publ...1/ChartNo1.pdf


Another recommendation to understand and to use ENCs with all their possibilities is David Burchs book:
Introduction to Electronic Chart Navigation: With an Annotated ECDIS Chart No. 1 Paperback – February 22, 2017

[MazatlanMexico]

Thank you all for your help...well explained!!!

[rgleason]

See FAQ, added the second pink circles.
https://opencpn.org/wiki/dokuwiki/do...nger_symbology


Any suggestions/improvements?