USS Dean II (SP-98) was an armed motorboat

Motorboat

A motorboat is a boat which is powered by an engine. Some motorboats are fitted with inboard engines, others have an outboard motor installed on the rear, containing the internal combustion engine, the gearbox and the propeller in one portable unit.An inboard/outboard contains a hybrid of a...

 that served in the United States Navy

United States Navy

The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

 as a patrol vessel from 1917 to 1918.

Dean II was built as a civilian

Civilian

A civilian under international humanitarian law is a person who is not a member of his or her country's armed forces or other militia. Civilians are distinct from combatants. They are afforded a degree of legal protection from the effects of war and military occupation...

 motorboat in 1915 at Greenport

Greenport, Suffolk County, New York

Greenport is a village in Suffolk County, New York, United States. It is located on the north fork of Long Island. The population was 2,048 at the 2000 census....

, New York

New York

New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...

. The U.S. Navy, which inspected her for possible naval use as a patrol boat

Patrol boat

A patrol boat is a relatively small naval vessel generally designed for coastal defense duties.There have been many designs for patrol boats. They may be operated by a nation's navy, coast guard, or police force, and may be intended for marine and/or estuarine or river environments...

 in World War I

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

 and deemed her a "well built and seaworthy boat for her size", acquired her on 2 May 1917 under a free lease

Lease

A lease is a contractual arrangement calling for the lessee to pay the lessor for use of an asset. A rental agreement is a lease in which the asset is tangible property...

 from her owner. She was commissioned

Ship commissioning

Ship commissioning is the act or ceremony of placing a ship in active service, and may be regarded as a particular application of the general concepts and practices of project commissioning. The term is most commonly applied to the placing of a warship in active duty with its country's military...

 on 10 May 1917 as USS Dean II (SP-98).

Dean II was assigned to the 3rd Naval District, where she performed patrol duty. In March 1918, she was ordered to be returned to her owner. Decommissioned

Ship decommissioning

To decommission a ship is to terminate her career in service in the armed forces of her nation. A somber occasion, it has little of the elaborate ceremony of ship commissioning, but carries significant tradition....

on 31 May 1918, she was returned to her owner on 16 July 1918.