The seven vessels that made up the P.V. type were initially named William H. Murray, Amagansett, Herbert N. Edwards, Martin J. Marran, Rollin E. Mason, Leander Wilcox and Rowland H. Wilcox. The trawlers were built at three locations in northeastern United States. William H. Murray, Amagansett, Herbert N. Edwards and Martin J. Marran were constructed at Rockland, Maine. Rollin E. Mason was built at Essex, Massachusetts and Leander Wilcox and Rowland H. Wilcox were constructed at Noank, Connecticut. The seven vessels that made up the P.V. type were of varying but similar dimensions. William H. Murray and Amagansett were the largest of the seven. They were long with a beam of and a draught of. They had a displacement of. Both were launched in 1912. Herbert J. Edwards, Martin J. Marrin and Rollin E. Mason had the same length and beam of the previous two, however, their draught was and had a displacement of. All three were launched in 1911 Leander Wilcox was long with a beam of and a draught of and had a displacement of. She was launched in 1903. Rowland H. Wilcox was long with the same beam as Leander Wilcox. However, her draught was deeper at and she displaced. Rowland H. Wilcox was launched in 1911. All seven vessels had a maximum speed of.
The seven P.V. type vessels were constructed as menhaden fishing trawlers for use in the Atlantic fishery. In January 1917, the Royal Navy demanded that the Royal Canadian Navy expand its patrol force to protect the shipping lanes around the Canadian Atlantic coast. However, the British had no intention of providing any of their fleet of trawlers or patrol vessels in support. As part of the Royal Canadian Navy's effort to increase the number of patrol vessels, inquiries were sent to the United States to acquire suitable vessels. Those inquiries resulted in the seven menhaden trawlers being purchased in New England. Commissioned into the Royal Canadian Navy, they took on new names. William H. Murray became P.V. I, Amagansett became P.V. II, Herbert N. Edwards became P.V. III, Martin J. Marran became P.V. IV, Rollin E. Mason became P.V. V, Leander Wilcox became P.V. VI and Rowland H. Wilcox became P.V. VII. Their 8-knot speed made them more suitable as minesweepers and they were converted into such with the addition of a QF 12-pounder gun placed forward. Entering service in March 1917, the seven trawlers formed a minesweeping flotilla based out of Sydney, Nova Scotia for the remainder of the war until April 1919. In April they were disarmed and resumed their former purpose as fishing trawler. They returned to their former names as well.
