Reply from my I-14 buddy.... where there are very few restrictions....
"As long as there isn't something in the class rules, it's fair game. (Assumes you aren't getting information that isn't readily available to other competitors.)
At the last two I-14 world championships, we saw a lot of boats with Velocitek Prostarts (can be purchased locally through CCI), which takes GPS readings to give velocity, heading, and even allows you to determine mid-line sag. On the Blue Footed Boobie, we sail with a GPS speedometer and a tactic micro compass."
My own impression is that I-14's spend more time in the water than looking at electronic guides, speedpucks etc.
The best of bloopers is at http://m.youtube.com/watch?feature=youtu.be&v=IPMoRr1Ju7E
Reply from my F18 buddy....
"Section C5 of the F18 rules Allows such devices.. sort of...
C.5 PORTABLE EQUIPMENT
C.5.1 FOR USE
(1) One righting line, minimum 4 metres long and 10 mm minimum diameter.
(2) One steering compass.
(1) Steering compasses.
(2) Mechanical timing devices. Mechanical wind indicators.
(3) Electronic devices that provide timing, heading, and heading memory but which do not transmit or receive data
(4) When required by the Notice of Race for long distance courses,organisers may require further equipment, such as VHF, mobile phone, GPS or tracking devices
, Emergency Positioning Indicating radio beacons (EPIRB) devices, knife, mirror, whistle, flares, flashlights, first aid set.
C.5.2 FOR USE
(1) Towing line of 15 metres long and 6 mm minimum diameter.
(1) When required in the Notice of Race, one paddle with minimum total length of 1000 mm. The paddle blade shall be minimum 140 mm etc."
Seems to me F18's have the best of both worlds.