How strong is the current in a swim spa?

Current strength is usually described either as a pace (minutes per 100 yards) or as a water speed in miles per hour, and manufacturers do not measure it consistently, so treat published numbers as marketing rather than a standard. In practice: - Entry jet systems suit an easy to moderate pace and are best for water walking, tethered swimming, and resistance work. - Mid-range jet systems handle a comfortable recreational lap pace for most adults. - Propeller and paddlewheel systems reach the fastest paces available and are the only category competitive swimmers generally rate as adequate for training. The only reliable test is to swim in the model you are considering, at the speed you actually swim, for at least five minutes. Current that feels strong for thirty seconds can feel unbalanced or turbulent over a real set.