Your story takes me back to the time when I coached high school track and each year we went out of state for a big invitational track meet.
Since we did not do this very often the athletes loved to go on overnight trips for meets (for some their first ever trip out of town without their parents) and we often told them not to go in the pool. Even if they had no intention of swimming laps they might begin to play around in the pool and what started out as recreation turns into an unintended workout.