RFE Anchor alarm feature request (Bearing, distance)

[Ric121]

Request: Add "Bearing to anchor" and "Distance to anchor" fields to the interface to calculate the actual position of the anchor and the exclusion circle.

Rationale:

• Setting the anchor at the boat position is not very practical as you don't have time to interact with openCPN during the manoever.
• Several popular apps use this kind of settings (Anchorwatch, Anchor Alarm, etc...)

Details:
See attached file for an overview of the interface change. Please excuse the poor hand writing.
The actual position (coordinates of the circle center) would be
Latitude/Longitude corrected by the bearing to the anchor and the distance to the anchor as depicted in page 2 of the uploaded document.

Update: The bearing I mention should be the true bearing (or magnetic it doesn't matter), not the angle to the bow, as my skecth could be confusing. This is the one you obtain with a handbearing compass that everydbody should have on board.
I update a new sketch that I hope is better

WatchdogFR-02.pdf

[rgleason]

Singlehanded Anchoring Alarm This needs to be simple!!! Does not need to be complicated. So, it appears this would be one way to do it singlehanded.

1. Turn on OpenCPN and turn on "track"
2. Anchor normally and back down on the anchor to get it set.
3. In opencpn enter an anchor or waypoint,, right click and select copy lat/long. Then paste anchor lat/long into the plugin.
4. Plugin
   • Enter Anchor Location Lat/long
   • OR Rode length from markings and Bearing
   • Enter Bow roller to GPS Distance.
   • Enter Depth from sounder.
5. Options:
   • Enter bow location, so radius of chain and depth can be calculated.
   • Use a bearing off the bow for anchor location.
6. Adjustment later - Allow user to drag the anchor to a new position that looks right, when looking at a GPS screen that writes the location every 2-10 minutes.
7. Result shows rode, scope, depth, ratio and sets the anchor alarm.

[rgleason]

See https://www.cruisersforum.com/forums/f134/anchor-watch-external-alarm-trigger-283051.html#post3863686

For me it would become much more useable day to day if the waypoint onscreen was draggable. Or at least have an offset from boat distance & bearing input boxes when editing. Given up trying to record where the anchor was dropped, just never works very well so now take a guess based on track ( remember to add the distance from bow to gps receiver to the chain length to set the waypoint ring radius) then tweak it as the track shows the arc of the boat.

Which can actually change quite often which still comes as a surprise , reckon the chain caught on a rock or something last night, gusting 40 and holding well so other than letting out a bit more chain let it be around 2am Yellow track was yesterday, red from midnight,

Easiest way to get the waypoint ring to match the boat swinging arc is drag it until it looks right. If it is stuck then clears the alarm will trigger so I know something has happened.

Another great addition would be an option to right click, paste lat & long which had just been copied from a waypoint, digital degrees are a pain when you work in degrees, digital minutes.

Sending a signalk delta message if it triggers would be a cool feature as well, though not too hard to write a little script to do that.