Introduction to Precision Orienteering

Precision Orienteering, or PreO, (also called Trail Orienteering, or Trail-O) was developed as an alternative to classic foot orienteering, in which people can compete equally regardless of mobility limitations. Instead of navigating cross-country to locate control points, you are required to stay on certain roads and trails (defined in the Course Setter's Notes), and solve challenging problems in map/terrain interpretation.

Your map will look like a normal foot-orienteering course, with a Start, a series of numbered control circles, and a Finish. Control descriptions (a clue sheet) will be printed on the map. Differences between a PreO clue sheet and a regular clue sheet are described below. You will travel along the permitted roads and trails until you reach a decision point or "viewing station", designated by a small placard on the side of the road, with the control number. The viewing stations are not shown on the map. From the viewing station, you will see a set of one to five control bags in the terrain. Your task is to decide which, if any, of the bags is located at the center of the control circle on the map and is correctly described by the control description.

You will have a punch card with six columns for each control, labeled A, B, C, D, E, and Z. From the viewing station, you will be able to see all of the bags. Think of them as labeled from left to right as A, B, C, etc. We use the phonetic alphabet terms Alpha, Bravo, Charlie, Delta, and Echo to refer to the bags. A short distance from the viewing station will be a stand with a punch, where you will punch your card with your choice. If the left-most bag as seen from the viewing station is the correct solution, you will punch A; if the second from the left is the correct one, punch B, etc. If none of the bags is correct, punch Z. We refer to this as a Zero control. Once you punch your card, you cannot change your choice, so be careful.

You are allowed to travel along the permitted roads and trails to get additional information or other views, but a friendly warning​—​perspective changes from different vantage points, so make sure your choice is valid at the viewing station. And remember that "none of the above" (i.e., Z) is always an option.

On your clue sheet, you will see the usual symbols for each control. However, the second and eighth (last) columns are used differently. The second column shows how many control bags there are to select from. For example, if there are four bags, the column will show A–D. The final column can optionally be used to clarify the general direction in which you will be looking from the viewing station toward the controls. For example, a downward pointing arrow indicates that you will be looking south, so the approach to the viewing station is to the north of the control circle.

Although PreO is designed so that people with physical limitations can compete equally with others, there is still a time component. First, there is an overall time limit published for the course. You will have one point deducted from your score for each five minutes, or fraction, that you are over the time limit. For example, if the published time limit is two hours, then a time of 2:01:00 results in one point deducted; 2:13:00 results in three points deducted (i.e., two 5-minute periods plus a fraction of a period). Second, there will be one or more timed controls, generally at the beginning and/or end of the course. The timed controls serve as tie-breakers when two or more competitors achieve the same overall score.

The main features that distinguish timed controls are:

At a timed control, you will sit in a chair and hand your punch card to the monitor. The monitor will tell you how many problems are to be solved, and how many bags there are, and point them out in the terrain. At that point, you will be handed a set of papers or cards (one for each problem), and the timing starts. Each paper will contain a map section, correctly oriented, with a single control circle, a single clue, and a row of possible answers (for example, if there are six control bags, there will be boxes labeled A, B, C, D, E, F). You are to determine which bag is correct, and either point to the corresponding letter, or announce your choice using the phonetic terms (i.e., Alpha, Bravo, …). As soon as you indicate an answer, go on immediately to the next map. Once you have answered the final problem at the control, the timing stops. The monitor marks each of your choices and the total time on your punch card.

At each timed control, you are allowed a maximum of thirty seconds times the number of problems to make your selections. The monitor will warn you fifteen seconds before time elapses. Each incorrect answer (or unanswered problem) incurs a sixty-second penalty. Time spent at timed controls does not count against the overall time limit for the course.

If you're interested, the official U.S. rules for PreO are on the Orienteering USA website ( (see section D). The international rules are available here (