Not sure exactly what happened, and even if the body is recovered, they still will not be entirely sure.
The following is entirely my opinion of what may have happened based on my experience as a diver and have both witnessed and read about many such accidents. My condolences go out to his family and all those affected by his death.
The dive was a bouy dive for scallops. What that means is the boat does not set an anchor, only drops a weighted bouy. There is no structure on the bottom, no ship wreck to follow. Typically, just blank sand with maybe some reef rocks. The diver was probably a semi-experienced NJ wreck diver who is used to a boat anchoring to a wreck. This allows the diver to hang onto the anchor roap on the way up and down, and also to tie a wreck reel (spool of line) to the anchor so they can find their way back.
On this dive the diver proabably did not tie into anything and lost his way. If there was any current flowing he may have been swept quite some distance from the initial area with out even realizing it. When his gas (either air or a mix called nitrox) supply was getting low he probably started looking for the shot line (weighted bouy) and could not find it. At this point a highly experienced diver would stop looking and send up their own inflatable bouy and surface using this hoping the bouy would be seen from the boat. My guess is this diver continued to look for the shot line in a panic and probably expired most of his gas supply. When his gas was either gone, or dangerously low, he probably bolted for the surface, probably suffering an embolism and a mild case of the bends (tough to get severly bent in 110 feet of water). He may have surfaced, but proabably did not. If he did surface, my guess is that he did not drop his weights and or bag of scallops and that pulled him back down and with the ensuing panic, embolism and bends he probably drowned.
Hey Dan - ever read The Silent World by Jaques Cousteau?
The first chapters talk about the first aqualung experiments.
Old Jaques would remark how (after the gear became commercial)amateur divers were routinely going to depths that he would not attempt without preparation. He was using 80 feet as a threshold limit between pro and amateur.
Whenever I read or hear about lost divers I always reflect back to that book. So much can go wrong and the pseudo narcotic effect of being under water took its toll on a lot of divers. Also your body burns a lot of calories to maintain core temperature.
Compound that with panic....!
I have not read silent world, but I will have to pick it up.
80 feet is typically a good depth for beginners to stay within. Problem is, in NJ most of the diving is 80-100 fsw. When I was wreck diving hard (before my daughter) I tried to keep it shallower than 300 fsw. Yeah, noting like being 100 feet inside a shipwreck at 250 feet and having your light stop working..... ahhh fun times....
There are so many things that could have happened, it's hard to know. Certainly, getting swept far away from your boat is easy and could have been the case, but do we even know the boat was adrift and not anchored? Panic is often the cause of problems underwater. When I was big into diving, I did the cave/cavern diving scene for a for years. That can drive you into a panic quick if your so inclined. Nothing like having to take off your tanks to squeeze your body through a narrow cave...and knowing that if you have a problem, you can't just swim to the surface, in most cases it's just rock overhead. And losing the line is just about certain death. Yep, fun times.
I think I know what probably happened...has anyone seen that new show Surface? It could explain it all.
Seriously though, you gotta feel for this guys family. Hopefully they will find him to bring some closure.