SCY vs SCM vs LCM: Swimming Course Types Explained
Short Course Yards (SCY), Short Course Meters (SCM), and Long Course Meters (LCM) are the three pool formats U.S. Masters swimmers race in. They differ by pool length — 25 yards, 25 meters, and 50 meters — which changes both the distance you cover and how many turns you make, so the same swimmer records a different time in each course.
The three course types
A "course" describes the pool a race is swum in. Short course means a 25-length pool; long course means a 50-meter pool. Because the pool length sets how far you swim and how often you turn, times are tracked and ranked separately for each course.
In U.S. Masters Swimming, Short Course Yards is the most common format because most American pools are 25 yards. Short Course Meters and Long Course Meters use metric pools and are the standard internationally and in the summer season.
| Course | Abbreviation | Pool length | Common use |
|---|---|---|---|
| Short Course Yards | SCY | 25 yards | Most U.S. Masters meets |
| Short Course Meters | SCM | 25 meters | International and winter meters season |
| Long Course Meters | LCM | 50 meters | Olympic-style pools, summer season |
Why the same swim produces different times
Two things change your time between courses. First, distance: a meter is about 9 percent longer than a yard, so a 100-meter race covers more water than a 100-yard race. Second, turns: every wall gives you a fast push-off, and a 25-length pool has twice as many walls as a 50-meter pool over the same nominal distance. More turns means more push-off help.
The combined effect is that, for the same swimmer and effort, Short Course Yards times are fastest, Short Course Meters times are slower, and Long Course Meters times are slowest. That is why you cannot read a yards time and a meters time side by side without converting.
How to compare times across courses
To compare a time in one course with a time in another, convert it. A conversion multiplies the time by a course factor and adds a per-event adjustment for the difference in turns. Going from yards to meters, times increase by roughly 11 percent before the turn adjustment, but the exact factor depends on the stroke and distance.
Rather than estimate by hand, use the Openlane Time Converter, which applies the correct stroke- and distance-specific factors automatically once you pick the event and the two courses.
Which course should you focus on?
If you compete mostly in the United States, Short Course Yards will be your primary course, and your yards times are the ones most meets and USMS standards are built around. Long Course Meters matters most in the summer and for anyone chasing international or Olympic-style benchmarks. Short Course Meters shows up in the winter meters season and at international Masters meets.
Openlane is an independent analytics project and is not affiliated with, endorsed by, or operated by U.S. Masters Swimming.
Frequently asked questions
Is SCY faster than LCM?
Yes. For the same swimmer, Short Course Yards (SCY) times are faster than Long Course Meters (LCM) times, because a yard is shorter than a meter and a 25-yard pool has more turns — and each turn adds a fast push-off. Short Course Meters (SCM) times fall between the two.
What pool length is each course?
Short Course Yards (SCY) is a 25-yard pool, Short Course Meters (SCM) is a 25-meter pool, and Long Course Meters (LCM) is a 50-meter pool.
Can I compare a yards time to a meters time directly?
No. Times in different courses are not directly comparable because the distance and number of turns differ. Convert one to the other first — the Openlane Time Converter does this using the stroke- and distance-specific factors.