Chris,
Check into kattack.com
Not sure if you can have it relay to a computer instantly to track live but it might be worth checking into.
These guys brought units to Buzzards Bay Regatta on the 505's and several college regattas this fall (the team racing was really cool to watch). It is a small unit that can strap onto the mast or etc. We want to get them at my school for reviewing practices after.