OpenCPN User Icons
OpenCPN is open source (free) marine navigation software and is available from the OpenCPN Website. In OpenCPN, a user can install his or her own icons to create markers on the navigation maps. I need prescription glasses to read or see properly and some of the generic markers provided with navigation maps are quite small. I created these marker icons somewhat bigger so that I can see them without the need of my glasses.
These markers are calibrated and can be used for a number of requirements - including navigation, search patterns, bouy and channel markers, general information and many other uses. All the markers are named individual files and you can install all of them or only the ones you prefer.