Barry is author of the book, ‘999 Updated Questions on the Rules of Golf 2012 - 2015’ and writes a regular blog of miscellaneous content on the rules of Golf at www.barryrhodes.com

With the increasing use of Distance Measuring Devices (DMDs) on the golf course there is much confusion as to what is permitted by the Rules and what is not. I hope that this overview of the issues will help clarify the situation for you.

• The most important point to remember is that golfers may only use DMDs in competitions where the Committee has implemented a Local Rule allowing players to use devices that measure or gauge distance only (Note to Rule 14-3). Always check the Local Rules before starting a competitive round.

The following points assume that such a Local Rule is in operation.

• Any device may be used, notwithstanding the technology involved, providing it only measures distance. The use of a DMD that is designed to gauge or measure other conditions that might affect a player's play, like gradient, wind speed or temperature, is not permitted, regardless of whether such an additional function is used or not, and even if that function is disabled.
   
• Multi-functional devices, such as smart phones with a distance measuring application, may be used to phone, text or email (subject to any club or course regulations) – provided the purpose is not a breach of the Rules, e.g. you are not asking for advice.
   
• When a multi-functional device also has features or applications that gauge or measure other conditions that might affect a player’s play, such as a temperature gauge, compass or anemometer, this would render it non-conforming regardless of whether these other features or applications are used or not. E.g. you may not use an iPhone for distance measuring in competition as it has an inbuilt compass that cannot be deleted.
   
• Players may share a distance measuring device, providing in doing so they do not unduly delay play.
   

If you are still unsure as to the circumstances under which you may use a distance measuring device in a competition the following flow chart, issued in March by the R&A, should resolve any remaining questions that you may have.

Good golfing,