Are velocitech speedpucks legal for racing?
The relevant rule is IHCA General Class Rule 16.3:
16.3 Compasses with brackets or electronic devices that provide timing and heading memory but which do not transmit, transfer or receive data are permitted. The use of navigation and speed
metering equipment is illegal unless specifically allowed in the individual boat rules or by the Notice of Race for the particular event or regatta.
It's the "receive data" part that makes them illegal. If they didn't receive a GPS signal, they'd be legal.