Very pimp!
I looked it up and the velocitec 'speed puc' retails for £230 on line. It is waterproof. the back screws off to reveal the battery compartment. The rest of the electonics are in a seperate waterproof compartment. It give instantaneous speed, max speed and indicates relative heading changes (i.e. wind shifts). The display is really clear even when at the back of the racks. It can record lots of data which you can down load to your PC. Sounds really good. Weighs 285gramms, so 2/3rds the weight of my rudder stock.
Ooh can it be included in the hull weight!

What would be really good would be the BMW oracle americas cup team sunglasses with telemetry sent to the lenses (head up display style).