Billy, Contrary to a lot of published material, Halibut will travel high and far for a bait making the right moves. You can fish pretty high off the bottom for Halibut if the visibility is good. Unfortunately most people do not know when the visibility is good near the bottom. Even when it looks great at the surface, it is probably not so good on the bottom. Of course the opposite can also be true . I have seen Red Tide days, where the bottom was very clear. Most harbors are going to be pretty low visibility nearly all of the time.
Most baits are going to take full advantage of both the sinker and hook leaders too. They use most of the length to stay above the bottom. Generally, longer hook leaders should be combined with shorter sinker leaders. Keeping your bait in the "Zone" means keeping it where a target fish is likely to see your actively struggling bait. And that is not just the fish directly below it, but the ones off to the sides. The lower you keep it, the better ground coverage you get on the average day. Although the tradeoff is that you pick up a lot more snags and debris that way.
Overall, I would guesstimate the average visibility of our inshore fishing here in SoCal to be about 5-6'. Generally, the deeper you go (and further from surf zone), the better the visibility. Obviously other factors will effect the visibility like runoff, current, surge etc. The later (in the morning) you go, the better the light you will get reflecting off your bait (extending your range). Even though you can catch the fish away from the bottom, most anglers are going to bet on the conditions favoring lower presentation.
All that being said, the visibility has been pretty darn good all over for several weeks now
And a low presentation can be a bad thing for some of the nicer fish to bycatch
