noun
long course; 50-meter pool lane
Used in competitive swimming to refer to a lane in a 50-meter pool, as opposed to a 25-meter short course (短水路).
See also: 短水路
この大会は長水路で行われる。
This competition is held in a long course (50-meter pool).
長水路の記録は短水路
It is said that long course records are harder to achieve than short course records.