With satellites, Offshore sailing boats (AND ships) can be tracked in real time. They sail with transponders on board that communicate with stations on shore.
The
Bermuda 1-2 is currently underway with the first boats arriving at Bermuda as I post this.
http://www.bermuda1-2.org/
Click on "Tracker" and wait a few seconds for the connection to settle down. Then "Peck" around ..zoom in..drag around...and see what is there...
ALSO: Read NOTES for an ongoing text of what's going on in the fleet heading to Bermuda.
NB