Hey jacked55 - what type of leader are you using? Hook size? Also, note that when a coho strikes, the float might not actually take a dive! Watch for any unusual movement of the float and gently, but deliberately, lift the rod tip. This is classic roe fishing at its best, and mastering the setting of the hook is critical.
Anyway, I use 6 - 8 lb leader and size 4 hooks. If the fish are spooky or the water is clear, try experimenting with fluorocarbon leader. Length about 2 - 3 feet. Anything longer and you actually are at a disadvantage detecting the strike.
Good luck and have fun catching BITING fish...
I don't remember seeing my float dive at all on any of the coho that I hooked. The float barely wiggled but I could see the flash of the fish in the water while it tried to shake the hook out of its mouth.
Small presentations are the key. I don't use anything larger than a size #4 hook (unless I'm using hardware) when targeting coho and only Gammies for me.