Bjorn - i've fished similar "cuts" in maui and found, the deeper i went, the better i did. started with floating lines, then to intermediate, and so on - unless you're seeing bait busting on the surface or get lucky with cruising fish - i think the best bet is to get some weight on that fly, some sinking line, and let your fly get down before the retrieve. start with short casts close in to the reefy goodness, work your way across through the deeper water, cast as far as you can cast - vary the retrieve, vary the depth, vary the fly - lather, rinse, repeat. also - put some wire between your leader and your fly - lots of toothy stuff out there.
or better yet - get a spinning rod, put a heavy wooden bobber on it with a jig or something dropped a few feet below, vary the speed of the retrieve, use the bobber as a surface attractor (a la trolling for bill fish) - cast it a mile further than your fly rod, cover more water, catch more fish
oops, sorry - this is a fly fishing board....