When people first hear about SCUBA diving, many ask this question. My standard response is “to the bottom”. While I am joking a bit, unless you’re doing a wall dive, this is usually the case.
Part of the answer depends on the location of the dive: off the coast of New Jersey, the bottom slopes gently for the first 30-50 miles. Shortly after this we hit the Continental shelf, commonly called the Canyon. Here the depth drops sharply to several thousand feet. Obviously our diving is on the gently sloping bottom.
About 3 miles off the beach, the depth averages about 60ft. After 20-30 miles, there are some great wrecks in 130 ft. The bottom slope does vary from place to place. There is narrow trough cut by the Hudson river commonly called the Mud Hole. Inflatable Water Slide It is deeper than the surrounding area, but the outflow of the river makes the conditions more challenging.
The rest of the answer depends on the diver’s experience and training:
Novice divers should stay shallower than 60ft, until they develop the skills and comfort in the water necessary to go deeper.
Advanced divers go between 60 and 130 ft. At this point they carry additional safety equipment necessary to perform these dives.
Technical divers go beyond the 130 ft range down, sometimes in excess of 300 ft. These divers have spent years training and practicing for these dives. They carry redundant gear and practice techniques to survive equipment failures. Many famous shipwrecks are in this range: the Andrea Doria, the U-869, the Black Sunday wrecks including the S.S. Carolina. These all fall in this range of technical dives.
How deep do I personally go? Well, I teach Technical Divers. While I enjoy spearfishing and photography in the 50-130 range, we can often be found diving in the 180-250 range.