USCGC Katmai Bay [WTGB-101]

USCGC Katmai Bay [WTGB-101]


Icebreaker Tugboat

Sault Ste. Marie, MI

USCGC Katmai Bay, docked in Muskegon, MI, 7/26/2019. Brendan Falkowski


Build Information

Year Built: 1978

Builder: Tacoma Boatbuilding, Tacoma, WA

Hull #–

Registry: US –

IMO # —

Laid Down: November 7, 1977

Launch Date: April 8, 1978

Delivered: —

Commissioned: January 8, 1979


Katmai Bay was the lead ship of the Bay Class USCG Icebreaking tugboats. The Bay class vessels were designed to replace the Coast Guard’s aging class of 110′ harbor tugs. The Bay Class tugs feature a strengthened icebreaking hull, and is capable of breaking 20 inches at continuous speed and 6-9 feet while backing and ramming. The Bay Class tugs are also equipped with a unique “bubbler” hull air lubrication system. The bubbler pushes air through ports on the cutters hull, allowing for an upward flow of air and water along the hull, reducing friction and increasing efficiency.

There were 9 Bay Class tugboats constructed for U.S. Coast Guard service, and 6 of them are stationed on the Great Lakes. Those are the Katmai Bay, Bristol Bay, Mobile Bay, Biscayne Bay, Neah Bay, and Morro Bay.


  • Service Life Extension Program, U.S. Coast Guard Shipyard, Baltimore, MD, 2018.

General Stats

Length Overall: 140′

Breadth: 37’06”

Depth: 12′

Vessel Type: Icebreaker Tugboat

Icebreaking Capability: 20” freshwater ice at continuous speed, 6-9′ freshwater ice backing and ramming

Propellers: 1

Rudders: 1

Crew Compliment: 17 [3 Officers / 14 Enlisted]

Engineering Equipment



Engine Type: Diesel Engines

Engine Manufacturer: Fairbanks Morse, Beloit, WI

Engine Model: 10-38D8-1/8

Number of Engines: 2


Motor Type: Diesel-Electric

Motor Manufacturer: Westinghouse Electric, Pittsburgh, PA

Rated HP: 2500 BHP



USCGC Katmai Bay [WTGB-101] – 1978-Present

Owner: United States Coast Guard, Washington D.C.

Operator: United States Coast Guard, 9th District, Cleveland, OH

Flag: United States

Home Port: Sault Ste. Marie, MI

Station History

  • Sault Ste. Marie, MI – 1978-Present

Her Story

USCGC Katmai Bay was constructed in 1978 by Tacoma Boatbuilding of Tacoma, WA, as an icebreaking tugboat for the U.S. Coast Guard. She was the lead ship of her class, and was laid down on November 7, 1977, being launched on April 8, 1978. Following completion, she sailed to the Great Lakes where she was commissioned on January 8, 1979, and took up station at Sault Ste. Marie, MI.

In 2018, Katmai Bay went to the U.S. Coast Guard’s shipyard in Baltimore, MD, where she underwent her Service Life Extension Program (SLEP) refit. She returned to the Great Lakes at the end of the year.

USCGC Katmai bay remains an important asset to the Coast Guard’s Great Lakes icebreaking fleet, and assists in keeping marine traffic moving during the winter months.

Compiled By Brendan Falkowski

Updated on December 9, 2021.


“CGC Katmai Bay”. United States Coast Guard, N.d. Accessed 9 December 2021. <>

LeLievre, Roger. Know Your Ships 2021. Marine Publishing Co., 2021. Pp. 86

U.S. Coast Guard. (2015). Welcome Aboard: USCGC Biscayne Bay (WTGB 104). [Brochure].