Don't always assume that the strike zone is directly in the light. Years of fishing the bridges and docks in the area you are talking about has taught me that. Here is my technique, maybe you can get some use out of it.

#1) No swivels, just your knot of choice between your main line and shock leader, I use a knot called a "cove knot" or "water knot" taught to me a long time ago by a guide. It has never failed me and it leaves just enough of a knot so I can put an egg sinker above it and it won't pass over. Use an egg sinker just big enough to barely pin to the bottom and about 3 feet of flourocarbon. That will let those big shrimp swim up off of the bottom a bit.  

#2) I always start directly in the brightest light. No bites leads me to the perimeter of the light. I keep a log of all my trips and my largest fish have come from just outside the halo of light, especially around bridge pilings. I rarely change bait depth so if I strike out on the pilings with the bright lights I then move to the green and red lighted pilings and sometimes those are holding a lot of fish. If at last nothing I move to the inside of the bridge pilings of the brightly lit one and fish the dark shadows there. Sometimes those big fish I believe sit in that shadow line towards the light and actually run through the boards to attack the bait. Just be patient, don't give up too soon but don't stay too long with no bites. One thing  I do a lot if I am not getting bites is pick the weight up about three feet and drop it again, about every minute, letting the bait fall back with the tide again.

Hope this helps.

c

Eventually, all things merge into one, and a river runs through it. The river was cut by the world's great flood and runs over rocks from the basement of time. On some of the rocks are timeless raindrops. Under the rocks are the words, and some of the words are theirs. I am haunted by waters.