What are the benefits of a countercurrent system? Can I regulate it?

A counter-current system can be used for swim training because it enables continuous swimming in one place. There are counter-current systems with one or two nozzles – where the double-nozzle systems form a wider jet that hits the left and right shoulder area. The swimmer therefore lies more stably in the current and can stay in it more easily. On the one hand, the performance of the counter-current system can be regulated by the addition of air into the water jet. The more air admixed, the more voluminous and powerful the jet becomes. Some systems also have pump output regulation. Such technology makes sense if there is only a length of about three meters available for swimming. In all other pools, the jet strength is regulated solely by the distance the swimmer is from the nozzle. Close to the nozzle, the jet is strongest – the further the swimmer moves away from the nozzle, the weaker the jet becomes. In training, this fact is utilized by alternately swimming closer to the nozzle and thus more powerfully, or letting oneself drift back and doing less powerful intervals. 

Counter-current systems should not necessarily be used for massage purposes because their nozzle output is too strong.