The "Emerald" wreck is probably the Hibiscus, a wood-hulled twin-screw steamer built in 1864 and commissioned into the U.S. Navy at that time. She saw service during the Civil War out of Tampa and Key West Florida. She was decommissioned in 1866 and sold in New York; later renamed Francis Wright, then renamed back to Hibiscus. While cruising off the New Jersey coast she broke a propeller shaft, took on water, and sank.
This is approximately what you’ll find on the wreck site today: twin engines with part of one propeller shaft missing. The size of the wreckage also matches that of the Hibiscus. Capt. Steve adds: "We do a lot of digging here and find quite a bit of stuff, but nothing that actually names the wreck, although we’ve dated artifacts from 1872 and even found U.S. Navy emblems on personal effects." the redundant power plants also point to a Navy ship - this is an expensive configuration that would be unlikely on a commercial vessel.
The Emerald is actually quite a small site to dive, since most of the wreck lies buried beneath several feet of sand. The boilers are about as broken-down as boilers can be, but the unusual dual steam engines provide myriad nooks and holes for Sea Bass and other fish. If you tie off a reel and sweep out over the clean white sand, you can find the holes dug by artifact hunters, down to the blackened wood remains of the hull.
Per Capt. Al of the Sea Lion; Seems the wreck was heavily encrusted with mussels and every time the hook bit it pulled out. I don’t deal well with “hook rejection”.
Once the unpleasantness was over things got MUCH better. Coming up from the first dive a diver new to the Sea Lion came over the side and mentioned he had a lobster. I don’t think he knew how good a grab he had made because when the bag was opened there was a 5 pound lobster in it; just inside the legal size, another sixteenth of an inch it would have been too big. On the second dive a four pounder came up along with two other decent bugs, like I said things got much better. A number of bags of mussels also came up, not sure why the wreck had so many mussels on it as over the years it has never had any.
From Atlantic Divers; The Emerald is an unknown steamer at 80 feet. A great digging wreck, the Emerald was named by the late Capt. George Hoffman for it’s emerald colored bottles and the green copper piping that littered the wreck when it was first dove. Recent crates we’ve uncovered has led to evidence that this may be the wreck of the Alexander Oldham, a coastal steamer lost on Dec. 31, 1873. This wreck has many fantastic artifacts waiting to be found. Some of the items recovered so far have been bottles, china, silverware, beads, ink wells, bone toothbrushes, leather shoes, a clock and it’s key, and even a small, unmarked dinner bell. Above the sandy bottom lies four, almost buried boilers, the engine and twin prop shafts. The props are missing.