The manual, page 35 for a cp89 and another ?
says
NAV AIDS PRESENTATION Allows the Nav Aids presentation to be drawn using NOAA symbology when US is selected or International symbols will be used when International is selected. When selected these functions affect how the icons for Lights, Signals, Buoys and beacons are displayed.
Also, Raymarine says this:
12.0.1 Additional Functions on Chart page When on the Chart page you will notice icons of Buoys, Towers, Lights, Wrecks, Tide Stations and Port Icons. If the cursor is moved over the top of these icons a popup window will be shown with information about the icon.
I don't own one of these units, but there seems to be a lot f finfo about them, right on them.
Hmm, still wonder, just what was that symbol?