I've recently been asked to clarify the Class  position in relation to the TacTick compass and a range of  products coming on the market which use GPS transmissions to determine  speed and positon. An example is the Velocitek SpeedPuck - see

http://store.velocitek.com/SpeedPuck.

The TackTic compass offers a digital  alternative to the older style tactical compass but also includes a  simple time keeping device. It operates equally effectively in the  Northern or Southern hemisphere, but cannot provide speed or position  information.

Most other products use GPS transmissions to  provide speed and position information. While great for training, they  typically fall outside Interpretation 32 - see below, and therefore  cannot be used whilst racing in Tasar Class sanctioned events.

32. No electronic device which could be  used to increase boat speed or gain a tactical advantage shall be  attached to a boat or carried by a crew member, other than (a) time  keeping devices, and (b) compasses as allowed by rule C.2.2.g, provided  these cannot calculate speed or location information for use while  racing.