Under edit menu I find Manage custom waypoints symbols but when selected, I see None Found. I think you have to put your symbol in a special folder but I can find the path. Also will jpeg work?
Thanks
Yes, you're correct that "Manage custom symbols" is primarily for use with sending to and receiving from our older non-mass storage devices (GPSmap 60, eTrex, etc.). It can also be used to change a symbol's id once loaded, in case you have existing waypoints expecting a specific custom symbol id.
To answer your initial question if you're still curious, you can drop the images in /Users/<your username>/Library/Application Support/Garmin/Custom Waypoint Symbols/ to have them read in as options. The folder probably won't exist if you don't have any symbols yet. They should be named between "0" and "63", and we support png, tga, tiff, bmp, and jpeg formats. So, for example, "5.jpg" would be read in as custom symbol #5.
While technically you can use any resolution image, we scale it down to 24x24 for display in BaseCamp, and further to 16x16 for transfer to the device. I recommend using a square image for best results.
Once the symbol has been loaded it will appear at the end of the list you get when you change a waypoint's symbol.
Hope this helps!