Built in 1977 by the Louis G. Ortiz Boat Company of Krotz Springs, Louisiana (hull #27) as the Mary Lee Rivero for Mary Lee Rivero Towing Incorporated of Belle Chasse, Louisiana.

In 1995, the tug was acquired by the Bowhead Transportation Company Incorporated of Seattle, Washington. Where she was renamed as the Sadie Brower Neakok.

In 2001, she was acquired by Roger C. Niemeth of Anderson, California. Where the tug was renamed as the Miss Pill.

In 2011, the tug was acquired by Westar Marine Services Incorporated of San Francisco, California. Where she was renamed as the Fatcat.

In 2024, she was acquired by the Curtin Maritime Corporation of Long Beach, California. Where the tug was renamed as the Emma C.

In 2024, the tug was phased out of active service and was "laid up" at Long Beach, California.

Originally powered by two, Caterpillar 3508B diesel engines. Turning two, fixed pitch propellers, she was a twin screw towboat, rated at 1,550 horsepower.

In 2025, the tug was repowered with two, Tier IV compliant Baudouin 12M26.3 diesel engines. With Industrial DMT600DL reduction gears, at a ratio of 4.48:1. Turning two, fixed pitch propellers, she is a twin screw towboat rated at 2,400 horsepower.

Her electrical service is provided by two, Tier IV compliant, John Deere 4045TFM85A generator sets.