OpenData

The database of the OpenStreetMap's database contains a lot of geoinformation, which is quite useful for planning a boat trip.
OpenNauticalChart creates a seamark-overlay from this data, OpenSeaMap makes this available online. Chart packages are also available for download, here.
A wide variety of chart styles and applications have been developed around this idea. Especially the Inland Navigator will find all necessary information about bridge heights, lock times and even automated routing throughout Europe.

To complete the maps, information on water depth is essential: openDEM shows in which sea areas free bathymetry data is available.

The project lives from many volunteers who continuously update data!

 

AIS data exchange

ship spotting

Popular services like marinetraffic.com or vesselfinder.com do rely on numerous AIS station around the world.
Volunteers are collecting AIS-data within reach of their receivers and pass them to the servers. There are still areas, not yet covered!
Setting up a receiving station is simple and does not cost a fortune: Internet access, raspberryPi, a cheap DVB-T-stick and an old TV arial do the job.
The owner of an AIS station benefits from extra services offered by service providers, others have to pay for.