Most of the clarifications that The R&A receives in connection with distance-measuring devices (DMDs) along with the answers, are provided below.
Q. Can I use a distance-measuring device in a competition?
The use of a distance-measuring device during a round is allowed under the Rules of Golf per Rule 4.3a(1). However, a Committee can restrict the use of such devices via a Local Rule.
Q. What kind of distance-measuring devices are allowed by Rule 4.3a(1)?
A GPS, laser, smart phone, any really – provided the device meets certain guidelines and recommendations. The important thing to remember is that the device must only be used to access and measure permitted information. The player would be in breach of the Rules if the device is used to access prohibited information, such as elevation changes and club recommendation features. Even if a device has the ability to provide information that is prohibited, a player is still only in breach of Rule 4.3a(1) if he or she uses the device to access the prohibited information.
Q. What about multi-functional devices, such as a mobile phone, with a distance-measuring application?
As long as a Local Rule is not in place restricting the use of DMDs, a multi-functional device may be used, provided it is not to access information that, if used, would cause the player to be in breach of the Rules.
Q. If a player uses a smartphone to look up a weather forecast, is the player gauging the conditions?
No. Accessing weather reports provided by a weather station through an app or internet browser is not actively measuring or gauging the conditions and is permissible even if the Local Rule restricting the use of DMDs is in effect.
Q. My smartphone has an inbuilt spirit level as part of the functionality of the phone, but it is not part of the distance-measuring app. Can I use the phone as a distance-measuring device?
Yes, provided that you do not use the level in a manner that creates a potential advantage.
Q. My smartphone has a compass feature. Can I use the phone as a distance-measuring device?
Yes. A compass only provides directional information, does not gauge or measure variable conditions and is permissible even if the Local Rule restricting the use of DMDs is in effect.
Q. If we want to introduce the Local Rule restricting the use of distance-measuring devices what should it say?
The wording of the Local Rule (Model Local Rule G-5) reads as follows:
“Rule 4.3a(1) is modified in this way:
During a round, a player must not obtain distance information by using an electronic distance-measuring device.
Penalty for Breach of Local Rule - see Rule 4.3.”
Q. May players, whether not they are partners, share a distance-measuring device?Yes, but it is important that players do not unduly delay play.