From the article:
The MK 48 is propelled by a piston engine with twin, contra-rotating propellers in a pump jet or shrouded configuration. The engine uses a liquid monopropellant fuel, and the torpedo has a conventional, high-explosive warhead. The MK 48 has a sophisticated guidance system permitting a variety of attack options. As the torpedo leaves the submarine's launch tube a thin wire spins out, electronically linking the submarine and torpedo. This enables an operator in the submarine, with access to the submarine's sensitive sonar systems, initially to guide the torpedo toward the target. This helps the torpedo avoid decoys and jamming devices that might be deployed by the target. The wire is severed and the torpedo's high-powered active/passive sonar guides the torpedo during the final attack.
The MK-48 contains 650 pounds of explosives and can be launched up to 6 miles away from the target.
This video shows the MK-48 in action:
The same explosion from several other angles:
Torpedoes can also be launched from boats: