This is the Underpowered Curve Cast which has many presentation uses and can be used to cast around fish for drag-free presentations and also for long downstream drifts with stack-mends. In the way that I describe it – ie trajectory change – it can be used in windy conditions too. Just as in with Overpowered Curves, trajectory is often a missing key in explanations as to how these things work.
There is another use for it that I find more and more useful nowadays, and that is for throwing streamer patterns at moving fish. Fish do not want a fly swimming straight towards them – they will spook in the same way that you would spook if a bee flew straight at you – instead they want to be teased by a fly swimming away. In Tarpon fishing they call this the “going away shot” which is basically an “underpowered” curve that lands so that when the fly is pulled it is swimming away from the fish. It is a cast I use here in the Malaysian Jungle for Giant Snakehead as well.