In his 1976 book In the Ring of the Rise, Vince Marinaro had this to say about the riseform:
“Unfortunately, the riseform, important as it is, does not tell the fisherman very much…it tells him only that a trout is feeding and in a few circumstances it may tell him what kind of an insect is being taken. That is all. [The riseform does not] reveal the direction from which the rise came. It does not tell how far the trout drifted with the insect before the rise occurred…or whether he took the insect facing upstream, across stream, or downstream.
Though I thoroughly enjoy Marinaro’s writings, my own observations run counter to several of his conclusions. Indeed, the riseform does reveal the direction from which the rise came and, in the case of rivers, it does tell us whether the trout was facing upstream, across stream, or downstream.
Look carefully at a riseform. Small waves are created by the movement of the fish. These waves are not uniform in height across the riseform—there is a high and a low side. In the photo above it’s quite clear that the high side is on the left. The low side is to the right. An arrow drawn from the low to high side of any riseform points in the direction the fish is moving at the time of the rise. Our fish in the photo is moving to the left. (The dissipating waves outside the immediate riseform are from a previous rise.)
This high/low feature of the rise is similar to what happens when you stick your hand in flowing water. Water piles up on the upstream side. The faster the water, the higher the pile. In moving water, trout act just like our hand or any other type of current obstruction. Water is pushed up in front of their noses as they rise, creating the high side (always in the direction they’re facing). At the same time, their bodies function as a sort of shield against the current, resulting in the low side.
Stillwater riseforms have the same characteristics. But here the fish are moving while the water remains still. The fish’s nose still acts as an obstacle, and the effects on the riseform are the same as in a river. The high side of the rise always indicates the direction the fish was facing at the time he rose.
Gulper fishing offers an example of how this knowledge can be put to use. Hebgen Lake gulpers rise virtually every day of the summer, but their feeding is sometimes sporadic enough that predicting their direction of travel by watching for consecutive rises isn’t possible. The ability to look at a one-time rise and quickly decipher which way the fish is moving (and therefore where to cast your fly) pays real dividends at times like this.
Of course, just because we know the direction a fish is facing at the time of its rise doesn’t mean it will continue moving in that same direction. Fish on Hebgen and other lakes are notorious for random changes of direction. Still, the odds favor us assuming the fish remains on the same path, and casting our fly accordingly. We won’t be right all the time, but we’ll be right enough of the time.
Reading the rise is helpful in rivers too. Cutthroat and rainbows in rivers like the Lamar and Slough Creek often rise randomly as they cruise long, slow pools. The ability to predict their movements by watching their riseform is a huge help in getting your fly in a position to intercept them.
Trout feeding in back eddies present similar opportunities. Because the circular currents often disguise which way they’re facing, watching for the high side of the rise will give us enough information to make an informed presentation.
It takes practice to consistently pick out the high and low sides of a riseform. In the frozen moment of a photograph it may seem simple, but in real-time the rise happens in the blink of an eye. If at first you find it difficult to get the knack for it, don’t be discouraged. It is difficult. Many pros struggle with it. It is unquestionably an advanced skill, one requiring serious cultivation.
Here’s another photo of a riseform. Which way is the fish moving?
If you said left to right, you’re right. Make a good cast and the fish should be yours…