The Nuremberg Weatherdock company has developed a system that can fulfill exactly these requirements. These units are small portable transmitters that are mounted on the ships. These transmitters determine the current position by way of an integrated GPS module and transmit this position via VHF-
WinGPS is a navigation software for sports boats that can run on standard Windows PCs and notebooks.
The software is available in 3 different versions: Navigator, Pro and Voyager.