Is Your Golf Rangefinder ‘Legal’?
Of course what I mean by asking “Is your golf rangefinder 'legal'?”, is does it conform to the rules of golf? To get a full understanding, let's explore the joint USGA / R&A rule and decision that allow or disallow GPS and laser rangefinders to be used.
Rule 14/3b prohibits a player from using any artificial device or unusual equipment for the purpose of gauging or measuring distance or conditions that might affect his play. That alone would make all golf GPS and laser rangefinders against the rules and the penalty for the breach is disqualification. However, in 2006, Decision 14-3/0.5 was created to give tournament committees the option of adding a local rule that allows “distance-measuring devices”. If this local rule is in effect, then artificial devices that measure distance ONLY, are permitted. Any device that measures anything other than distance is prohibited even if you're not using those other features.
Most organized golf tournaments utilize the local rule, but it's always a good idea to read the rules sheet or check with the tournament organizer before using your golf rangefinder. Elite professional events and some high level amateur events do not adopt the local rule. You won't find these devices being used during a PGA or LPGA tournament, but if you're out there during the practice rounds, caddies and players will be using laser rangefinders and taking notes diligently.
So if you know that your golf tournament or golf group has adopted the local rule, then there is only one question remaining. Did you buy a GPS or laser that measures ONLY distance? If you laid out more cash for the laser binoculars that measure “slope”, they won't be allowed. Also, if you're using your smartphone with a GPS app, you are probably in violation of the rule because smartphones have weather and compass apps built into them. Golf's ruling bodies (the USGA and R&A) may have to modify or clarify this further in the future, but that's where it stands right now.
If you're playing a friendly game, then it probably won't ever come up and if your playing partners are really your friends, they probably won't care if you use your smartphone or your rangefinder with slope. With regards to posting scores for your handicap, the local rule is in effect. You should post all scores when using your distance-only measuring device.
I hope that explains it, but if not, please post your questions below.