Rangefinders in golf tournaments: what is allowed and what is not?

Precise distance information is a key element for a successful game of golf. Modern golf rangefinders, be it a laser rangefinder or a GPS golf watch, are aids that are widely used in popular sports. However, when it comes to using these rangefinders in golf tournaments, specific and often stricter rules apply. Fairness and the preservation of the sporting challenge are paramount. The R&A and the USGA, the leading governing bodies in golf, lay down clear guidelines that golfers should be aware of.

Rangefinders in golf tournaments: what the rules of golf say

The basis for the use of distance measuring devices (DMDs) in golf tournaments is Rule 4.3a of the Official Rules of Golf, which deals with the use of equipment. Since the last major reform of the Rules of Golf in 2019, it states that distance measuring devices are generally permitted. A course rule can prohibit this. Before 2019, it was the other way around.

If a course rule does not exclude the use of DMDs in a golf tournament, their functions are subject to strict rules: They may only be used to measure the distance between two points. Any other function that goes beyond this pure distance information is generally not permitted.

What rangefinders can (and cannot) do in a golf tournament

The variety of functions of modern golf rangefinders is impressive, but many of them are taboo in tournaments. Here is a detailed overview:

Permitted functions for your rangefinder in a tournament:
- Straight line distance measurement: a rangefinder is allowed to show the straight line and therefore the exact distance to the flag, bunkers, water hazards, trees or other fixed objects on the course. The measurement to the beginning, middle or end of the green is also permitted if the rangefinder is allowed in the golf tournament.
- Basic distance information: The device provides a pure numerical indication of distance without interpreting it or deriving additional recommendations.
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Prohibited functions:
This is the area where many modern golf rangefinders go beyond what is permitted and their use in a golf tournament can have consequences:

- Height differences (slope function): This feature, which adjusts distance to account for inclines or declines and displays an "effective playing distance" (also called "PlaysLike" distance), is prohibited. A golf laser or GPS watch with this slope function must be able to deactivate it and it must remain switched off during the entire round. Otherwise the device is not permitted.
- Environmental conditions: Functions that measure wind speed, temperature, humidity or barometric pressure and take them into account or display them when calculating distance are not permitted.
- Club recommendations: Devices that suggest specific clubs based on measured distance, environmental conditions or historical hitting data of the player are prohibited for the distance meter in the tournament.
- Swing analysis & technical advice: Any form of feedback on swing mechanics, posture or tips to improve stroke technique during the round is not permitted.
- Interactive maps / course management that go beyond distance: Features that display detailed topography, suggest recommended lines of play, or otherwise help determine strategy by displaying more than just distances are prohibited.
- Measurement and recording of shot distances during the current round: While the measurement of a distance to a target is permitted, the systematic recording and display of the lengths of individual own shots during the current round for statistical purposes or for later analysis is not permitted. A device may record this data, but it may not be retrievable during the tournament.
- General principle: In principle, any function that helps players to interpret the circumstances or make a decision that goes beyond mere distance information is prohibited.

Consequences of breaking the rules in a golf tournament

Disregarding these rules for rangefinders in a golf tournament can result in serious penalties. The use of an illegal device or the use of a prohibited function during the round usually leads to a general penalty, which means two penalty strokes in the counting game and the loss of a hole in the hole game. It is therefore very important to deactivate prohibited functions before the start of the round and to ensure that the device does not use these functions.

The rules around distance measuring devices in golf reflect the desire to keep the game fair and preserve its original challenge. Technology should not dominate the game or take away the need for players to interpret the conditions and make decisions independently. Everyone is encouraged to inform themselves about the specific course rules before each golf tournament, as the respective club may prohibit the use of rangefinders completely. Ultimately, the rules serve to protect the game and emphasize the personal responsibility and skill of the players.