In case anyone stumbles onto this page and is wondering about the S.S. Atlantus just inside the Delaware Bay off of Sunset Beach, Cape May, NJ, I just swam out to it Saturday, April 27, 2013. Was in the area and decided to give it a try and see what it was like.
Water was cold (in a dry suit, though), visibility was zero (i.e. gauges up to mask to see), and the current was killer. Got in the water, north of the wreck, about 45 min before low tide and had a hard 20 min swim to get to the wreck (which looked to be only 50 yards from shore). Apparently, the beach-goers must have thought it looked like a hard swim because they cheered when I got to the wreck!
Came up to the western most section from the south side and grabbed a piece of rebar to rest. Descended along the rebar for a bit, but never let go since would be blown off the wreck by the current. Also didn't want to surface into another piece of rebar. Couldn't see anything, even with a light. Back on the surface, clam walked (used bivalve muscles afixed to the hull as hand-grips) along the hull towards the gap in between the sections, but wasn't able to pull myself inside against the current. Eventually decided it wasn't worth it and let go...was immediately blow off the wreck (to the south) and swam back to shore.
Might be a fun dive given better vis. and much much less current. Probably won't go back...too many other new sites to check out.
If you have a good experience at the S.S. Atlantus, please post about it so we can get an idea when better times to visit are.