The engine drove a single propeller giving the ship a maximum speed of 9.5 knots (10.9 mph; 17.6 km/h).

She tended buoys along the Massachusetts coast, including the Cape Cod Canal.

[33] In addition to her regular buoy tending duties, Shrub contributed in other areas.

[25] On 6 August 1931, Shrub was servicing buoys near the entrance to York Harbor, Maine when she went aground on Black Rock.

The action of waves and tide rolled the ship off the reef and she ended up sitting on the bottom with only her mast and funnel showing.

[30] On 10 August 1931, the Portland Engineering Company was awarded a contract by the Lighthouse Bureau to salvage Shrub.

She left Portland under tow by the tug Clara H. Doane on 25 October 1931 with three pumps running to prevent her sinking.

[40] Bids were solicited for her repair and the contract was won by Brewer Drydock Company of Staten Island, New York.

[44] After the merger of the Lighthouse Service with the United States Coast Guard on 1 July 1939,[45][46] the tender became USCGC Shrub (WAGL 244).

She was assigned to the Boston Coast Guard District and continued her duties from her base in Chelsea.

During a gale in December 1939, Shrub went to the assistance of the four-masted schooner Albert F. Paul which had run aground in Narragansett Bay.

While Shrub's specific contributions to the war effort are unknown, the district's tenders were given a number of naval missions in which she likely participated.

These included maintaining wreck buoys, net tending, icebreaking, rescue, salvage, and marking areas swept for mines.

[45] At some point prior to 1941, Shrub was reassigned to the Coast Guard base at Bristol, Rhode Island.

[51] In 1962, Shrub was purchased by Betsy Ann Evers Browne, who documented the vessel as a yacht.

[52][53] Shrub sailed from Miami, Florida[54] on a fishing, diving, and treasure-hunting expedition on 20 January 1963 with Jack W. Browne, the owner's husband, as captain.

After negotiations between James B. Donovan and Fidel Castro, Shrub's crew was released and returned to the United States on 9 April 1963.