A trout is lying in the water column. It sees something drift by on the surface. It rises to intercept that something and it mouths the thing. As it does this and returns to its lie it leaves a riseform. A lot of writers have written about the riseform and how to interpret it. Views have ranged from vividly imaginative interpretations to physiologically impossible descriptions of “sipping” or “inhaling”.

I neither speak to trout to get their interpretation, nor do I have strange powers of divination that allow me to determine what motivates a trout. I do have a lifetime’s worth of observing trout rising and chucking flies, and occasionally even catching the odd one. This article, probably heretic in the annals of dry fly fishing, tells you what I have observed, and what you can see from hours of riseform videos about the trout riseform.