Waterline is a way to practice slackline or, rather, it means slacklining under certain conditions, in this case over water. It is precisely the fact that the line is suspended over water that determines whether or not we are doing waterline.
Waterline is not a
modality, but a context
It doesn’t matter if we are doing trickline
or rodeoline, or if the line is thinner or wider. You can trickline over water on a 2.5 cm line, or longline and rodeoline on a 5 com line over water. In any case we are talking about a waterline, either over a river, over the sea or over a swimming pool.