USS Observer (AMc-91) was an Accentor-class coastal minesweeper acquired by the U.S. Navy for the dangerous task of removing mines from minefields laid in the water to prevent ships from passing.

Observer was laid down 6 September 1941 by F. L. Fulton Co., Antioch, California, launched 15 January 1942 sponsored by Mrs. E. Stamm and placed in service 14 April 1942.

Observer was assigned to the 12th Naval District and was homeported at San Francisco, California.

It was subsequently purchased by an Alaskan charter company and refitted as a charter vessel that was pivotal in promoting legislation to protect the Tongass National Forest.

[1] This article incorporates text from the public domain Dictionary of American Naval Fighting Ships.