What is the difference between Short Course (SC) and Long Course (LC)? 

Short course takes place in a 25 yard (SCY) or meter (SCM) pool, whereas long course (LCM) takes place in a 50 meter pool. Short Course season normally runs from late summer/early fall through winter. Long Course usually begins in the spring and extends through the summer months. NOTE: When the pool is set up to begin practice for Long Course, there are fewer lanes available for each group's practice. Therefore, during this period, practice schedules may be adjusted to allow the appropriate number of swimmers per lane.