A ship is a large watercraft that travels the world's oceans and other sufficiently deep waterways, carrying goods or passengers, or in support of specialized missions, such as defense, research, and fishing. Ships are generally distinguished from boats, based on size, shape, load capacity, and tradition.
Cods - family Gadidae - are one of the most commercially important families of fish in the sea. As such, they have been fished to the brink of disaster. The book above is a fascinating study of the historical relationship between western civilization and the codfish.
The only freshwater representative of the cod family is the Burbot.