Adding the Third Dimension: Depth
By Mark Bachmann
We were all born into a three dimensional world. Those dimensions are described as length, width, and height (also described as depth). The difference between height and depth is determined by the perspective of the observer. Height occurs when an object is above you, such as observing a tree. Depth is when you are hunting a fish while you are standing on the bank of a river.
I had been following Jonah through each run. We had fished together many times. He was an excellent Spey caster, and his fishing technique looked to be very precise. I was quite sure he hired me (and other guides) because he was smart enough to realize it was cheaper than owning his own his boat, and he didn’t have to clean up the mess at the end of the trip. He also liked to have guides fish behind him so that he could gauge how well he was progressing with his fly fishing skill-set. Unlike some clients, he genuinely liked to share in the experience if a fish was caught from water he had already fished. When we started fishing together, I caught quite a few fish behind him, simply because I could reach steelhead that were beyond his range. Now, after several years of fishing together, he could regularly cast as far as me, and his approach was as stealthy as a ghost.
It had a day accompanied with blowing rain, and a wildly fluctuating river levels. My home river, the Sandy is often like that with surges of water, rather than steady predictable flows. Jonah landed a nice steelhead out of the first piece of water at day light. Now it was late in the afternoon, and no other steelhead had come to our flies. I had sat in the boat for quite a while watching Jonah fish down through the last run of the day. As usual his long, straight casts covered the best holding water. I noticed that the water had risen while we were fishing the previous run but was now holding steady. Jonah’s fly was landing way out in the river where the water was too fast to hold many fish. I wondered if it was getting deep enough to catch any fish or whether it was staying suspended in the upper layer of fast currents.
The way I read the water, any fish holding within the run were more likely to be closer to our side in the softer flows. My mind calculated the situation, gauging the water speed and depth, which sinking tip, casting angle, distance and fly would give me the best opportunity. Having fished here many times before, I knew that my boat was parked upstream from one of the sweet spots where the currents flowing around a large boulder had cut a groove in the gravel bed, offering a perfect place for a steelhead to rest before ascending the faster shallower water next to the boat. The boulder was only about thirty feet from the near shore, but the high colored water completely hid it from view. At this water level the top of the boulder would be about five feet deep. The fly would need to be at least three feet deep to be effective. My rod was already rigged with the right setup, which combined a floating Skagit head and eleven feet of T-11 for a sinking tip. To the end of the sinking tip was attached a 4-foot long 12-pound test leader. To that leader was attached a lightly weighted fly made entirely of pinkish orange translucent reflective Mylar.
After leaving the boat, I worked my way methodically downstream wading no more than five feet from shore, casting less than fifty feet of line. After covering seventy feet of water, my fly was somewhere close to the hidden boulder and there was a soft tick that was felt through the line. I repeated the last cast…nothing! I then waded up stream twenty feet, and proceeded back down stream, making a cast and swing every three feet. As the fly neared the boulder again, there was a soft nearly imperceptible tension on the line. I dropped the rod tip and let go of my shock-loop. The force of the current pulled the line tight, and the hook was set with a low sweep of the rod. At first there were only a few head shakes, then all hell broke loose with the heavy fish pulling many yards of backing from the reel, and me running downstream on the barren gravel bar after him. A couple hundred yards later the colored fifteen pound buck was landed and released. That fish had red cheeks and bright red stripe, but he also had silver rays in his tail, and was judged to be a repeat spawner that had not lost all of his mating color after returning to the ocean. My hook was stuck through an old healed up scar, where it had been hooked possibly a year before. The lesson here is that the longest caster doesn’t always catch the most fish. It is often the angler who puts his/her fly closest to the fish that scores.
Fly speed and depth are key points of presentation which will determine whether your fly will get attacked by a fish, or not. I’m a believer in the convenience factor. The closer your fly gets to a fish’s mouth, the more convenient your fly becomes. It is kind of like; if the closest grocery store were a hundred miles away, you couldn’t go there very often. If the closest store was only fifty miles away, you might go there every week. If one opened next door, you might visit several times a day.
If the fly is designed to stay on the surface of the water, the fly will be visible and its path, speed and location can be seen and always judged by the angler. The speed and path can be easily manipulated by the length and angle of the fly line. A floating fly line that contrasts with the color of the water is highly desirable because it gives the angler more visual control of the presentation. A long leader hides a bright colored line from the fish. Bringing fish to the surface to feed is always exciting whether the fish is a small cutthroat in a mountain stream, or a hundred pound sailfish eating a popper on the surface of thousand foot deep blue water. A normal size steelhead attacking a waking dry fly is no exception. That does reliably happen on certain rivers during certain times of the year when the water is moderately warm to moderately cool (50-60 degrees). It also happens with diminishing reliability when the water is both slightly lower and slightly higher than those temperatures. Steelheads rarely come to the surface when the water is less than 47-degrees. The water temperature in most Pacific Northwest rivers ranges from 47-44 through November, 34-38 degrees through December and January, and ranges up to 47-degrees by the end of April. For those six months it is very difficult to catch steelhead with flies that are presented near the surface of any river.
Winter steelhead will grab swung flies almost as well as summer steelhead, but they rarely move very far to intercept them. In other words, if you fish the Deschutes during August, you may expect that when the sun is off the water during both ends of the day, steelhead will often rise for flies that are several feet above them or come to flies that are several feet away from them. During low light conditions, during the warmer water months, many anglers fish their flies on or near the surface with floating lines. This surface activity usually tapers off once the sun is full on the water. However, it has been proven that they will still eat swung flies that are presented more closely to them with sinking tip lines.
It appears that high or low water temperatures keep many steelhead from rising for surface flies. This is probably a metabolic thing pertaining to the fact that they are cold blooded. The main factor that keeps steelhead from stationing near a river’s surface is water speed. In all rivers the velocity of the water flow is greatest near the surface. The deeper you go in the water column, the heavier water gets, which means that heavy water molecules create more friction on each other, and water slows down. There is also a tremendous amount of friction created by the interaction of the water with riverbed, which is like a piece of giant sandpaper. Also factor in that water is 800 times denser than air, so water molecules move against air molecules with less friction than other water molecules. So, a river moves fastest at the very surface. The popular equation is that in water which will hold steelhead and trout, ninety percent of the current speed is in the top ten percent of the water column. Getting your fly deep into a steelhead’s dining room with a sinking tip line is often the answer. Making your fly look like the organisms it has been dining on in the ocean is often the answer.
There is little doubt that a fly that is drifting with the current toward a trout or steelhead takes less energy to intercept than one which is swimming across the river. The faster or more erratic a fly is swimming across a river, the more difficult a target it becomes. Therefore, a fly that is swimming slowly while also drifting backward is both easy and enticing.
Your fly should follow the bottom contour with a preconceived plan. In many ways fishing with a swung fly is like fishing with drift gear. Both methods are very effective if done well, but both methods take time to learn. But then it is time spent on the water that we are all really after. The fish just give us an excuse to be there.