you have to adjust your setup accordingly. if your leader setup is for the 2-5 feet, then you need to change it so it can now reach 8-10 feet, or however deep these holes are. you also have to increase the sink rate of your fly/flies so they get to the depth of the hole quick enough they are in front of fish before the setup passes out of the hole. also realize that you won't be able to effectively fish the shallower water until you change back.

different setups will allow you to fish the hole differently too. if you make it really heavy, you can fish the drop off but that may be too heavy to effectively fish the rest of the hole. if you lighten up just enough, you can fish the rest of the hole effectively but won't have a good presentation for any fish that might be hanging right at the bottom of the drop.

if you are using nymphs, you can adjust your indicator so your setup will pass through the hole at different depths.