General
Most underwater hunting in New Jersey waters is done around some sort of structure. Surprise is often the key element to a successful hunt. "Get the drop" on a fish by rounding a corner or popping up over a wall while holding your breath. Don't use a light - this just spooks the fish. Instead, let your eyes adjust to the dark. This way you can see as well as they can, although they can still hear and feel you coming a mile away. Use your light only to peek into black holes, and keep one eye closed when you do, to avoid losing all dark adaptation.
Try to be the first person in the water. The fish will be in a relaxed and unworried state, and you will likely get the first one "for free". This is especially true if you are after trophy-sized Blackfish. Whether or not you score on your first shot, after that all the fish in the area will be spooked. This is because they produce "fear scents" - chemical excretions that warn other fish that there is danger. If you make a kill, you will put blood in the water, which is even worse. So make that first shot count. On the other hand, sometimes the scent of blood will bring in more fish, such as greedy Sea Bass, although more often just Cunners.
More: Spearfishing Techniques ...