Steamer or Steamship

Steamer is an early term for any vessel power by a steam engine rather than sails.

Shipwreck Delaware
The Delaware, an 1880s screw steamer

Early steamers were propelled by large paddlewheels. "Side-wheelers", with the paddlewheels on each side, were more seaworthy, and therefore more common in ocean waters, while "stern-wheelers", with a single large paddlewheel at the back, were more common as riverboats. Later, these were replaced by more efficient screw (or propeller) vessels.

Shipwreck Black Warrior
The Black Warrior, an 1850s side-paddlewheel steamer. There are no stern-wheelers in the region that I know of.
Click
This sketch of the Delaware shows the remains that you can expect to find of such a vessel.

Of note is the universal pattern of:

< bow - boilers - engine - drive shaft - propeller - rudder/stern )

and the fact that the boilers are always in front of the engine. Identify any one of these features on the wreck, and you can orient yourself in even the murkiest conditions.

Shipwreck Delaware boiler
Boilers on the Delaware. In the foreground is an intact one. Next to that is a collapsed one; there are four altogether. In the background is the engine.
steam engine
An old postcard of the City of Keansburg, the last of the New York commuter ferries, and one of the last steamships to ply local waters - until 1968.
steam engine
One of the Keansburg's two triple-expansion steam engines, at Allaire State Park.

Shipwreck Lexington
Type:
steamer, USA
Built:
1835, Jeremiah Simonson, New York NY USA
Specs:
( 207 x 21 ft ) 488 gross tons, 165 passengers & crew
Sunk:
Monday January 13, 1840
fire - 4 survivors
Depth:
125 ft - 150 ft

Type:
shipwreck, steamer
Built:
1911, Newcastle, England, as Etolia
Specs:
( 348 x 50 ft ) 3373 tons
Sunk:
Tuesday April 17, 1934
ran aground on Block Island - no casualties
Depth:
20 ft

Alexander Hamilton
Aground on a sandbar in Highlands, circa 1975

The Alexander Hamilton was the last of the steam-powered side-wheel riverboats of the Hudson River Day Line. Built in 1924, she ceased operations in 1971. A well-meaning group pulled the Hamilton from the mud in 1977 and moved her to a temporary berth along the east side of the Navy pier, planning to restore her as a museum. Unfortunately, at the new more-exposed location, the old vessel was sunk and reduced to scrap by a sudden storm in November of that year. The last records indicate that the wreck is still there, and you can even make out the outline on Google Earth.


Gammarus

Amphipod crustaceans typically range in size from 2 to 50 mm, although a few may be larger. Amphipods are common in aquatic ecosystems throughout many parts of the world, inhabiting marine, brackish, and freshwater environments. A few species are also terrestrial. Amphipod means "different foot", a reference to the varied legs that are evident in the illustrations, as opposed to isopods.

The order Amphipoda, which contains nearly 7,000 described species, is divided into three suborders: Gammaridea, Caprellidea, and Hyperiidea. Gammaridea, with more than 5500 described species, is not only the largest amphipod suborder but also contains all of the freshwater and subterranean taxa. Approximately 21 superfamily groups, 95 families and more than 1000 genera are recognized within this suborder.