Greg,
Ditto on what Chad said.......words of wisdom Buddy. I am alwasy adjusting my jig depth. Very important. You know you are too deep when your float points down river (hitting bottom). The depth varies throughout the run as well. You gotta hit it all. As the run tapers and gets to the tailout (GREAT PLACE EARLY AND LATE IN THE DAY) you will start hitting bottom. Often times the fish will hold in the tailout. Once I figure the depth of the tailout by adjusting my jig depth, I will cast upriver and it will have the perfect drift at the perfect depth once it reaches where the fish are holding in the tailout. When I move up the run, I will adjust deeper to fish the deeper water. I target areas when Im fishing or areas of the runs. Because the fluctuation in the bottom contour, I want to make sure my jig is in the zone when it hits the specific area Im targeting. I will then have to adjust for the next small stretch of the run as I move down or up river.
The bottom line is if you are not changing jig depth constantly, you are not working effectively. Ive been in an area and have seen a fish rise a few times. I will make several passes at him, adjusting my depth by just an inch or so. You will know when you find the depth he wants it.......BOBBER DOWN

If I eventually get too deep and start bumping bottom, I will work shallow it again about 1" at a time while I work him.
If I dont see a fish I will do what Chad said and adjust about 4"-6" at a time.
Remember that you want your float riding straight in the water. If it isnt, you are either bumping bottom or not mending your line enough.
Float straight up and down = perfect drag free driftConfidence is the key my friend......without a doubt. This is my #1 favorite method to target Steelhead. If I had only one rig to bring to the river, it would be my float/jig rod. I fish jigs where others would use other methods, including the fast riffly water. Once you watch your float slip under the surface for the first time, swing, and feel the surge of the steel on the other end.......its all over. You will then have the confidence you need.
Time on the water fishing is all it takes. You will get em. Man Im just overwhelmed with excitement......I WANNA GO FISHING RIGHT NOW
