Google Earth

To export GPS data into Google Earth, it should be encapsulated in a gx:track tag. Google provides libkml, a C++ library that should do that.

Google Maps
It is possible to embed Google maps into a webpage that is accessible from the both the boat and computers that are connected to the internet. Version 3 is now out and does not require an API key to use. There are no limits to the number of maps that can be generated by this API.

There is a tutorial on how to integrate it into the webpage using HTML5 in the getting started section of the API information page. The actual map code is written in JavaScript. When the function is initialized it is possible to set the starting longitude and latitude and the amount of zoom, which possibly could be input data from the boat.

There are different controls that are outlined in the link that can be used for various things including showing paths traveled and points of interest, such as way points, in the form of markers.

Looks straight forward and easy to incorporate into a webpage UI to make the GPS location of the boat more user friendly to read.