USS Avenger ( SP - 2646 ) USS " Avenger " ( SP - 2646 ) was an armed motorboat that served in the United States Navy as a patrol vessel from 1917 to 1918 . The second " Avenger " , a wooden - hulled screw yacht designed by J . Murray Watts and built in 1917 by Clement A . Troth of Camden , New Jersey , was inspected by the Navy on 11 January 1918 and acquired by the Navy in May 1918 under free lease from Philips J . Wunderle of Glenside , Pennsylvania , for service in the 4th Naval District . Assigned the identification number SP - 2646 , " Avenger " was commissioned on 29 May 1918 while she lay alongside Pier 19 , North Wharves , Philadelphia , Pennsylvania , with Chief Boatswain ' s Mate Philips J . Wunderle , USNRF ( her peacetime owner " called to the colors " ) , in command . Service history . Completing the initial phases of her fitting out by the second week of June 1918 , " Avenger " got underway for League Island on the morning of the 10th . She did not go far before she ran aground in shoal water near the back channel . With low water prevailing , her sailors prepared to wait for the incoming tide to refloat " Avenger " , but three vessels unexpectedly arrived on the scene and offered assistance . With their help , " Avenger " was soon waterborne and proceeded to League Island . However , since she was shipping water due to two damaged tanks in her bottom , the yacht proceeded thence to Camden , New Jersey , for hull repairs at the boatyard of Quigley and Dorf on 11 and 12 June . After receiving new planking and a coat of paint on her bottom , she returned to Pier 19 , North Wharves , the next day , 13 June . A week later , the vessel got underway at 1000 , " Captain " Wunderle at the helm , and headed back toward League Island , where she took on board her main battery , a three - pounder gun , and installed it the next day . Further provisioning and outfitting alongside Pier 19 followed : there , she received the balance of her armament , a pair of machine guns and four mounts , on 5 July . She obtained signals equipment and a large searchlight on the l1th and left Pier 19 the next day for Fort Mifflin , where she took on ammunition . Later that same day , " Avenger " got underway for New Castle , Delaware , reaching her destination that evening , and tarried there for the night . Pushing on the next day , " Avenger " reached Cape May , New Jersey , her assigned section base , on the 13th , via Reedy Island . The following morning , the erstwhile pleasure craft got underway for her maiden wartime patrol , which she conducted in waters off the McCrie Shoal Buoy . During her second patrol , ( 18 to 20 July ) she received information by wireless of enemy submarine activity near New York Harbor and promptly loaded her three - pounder to be ready for action . She soon received a signal from to patrol toward the McCrie Shoal for a distance of 10 miles in search of the U - boat reported in their vicinity . In the pre - dawn darkness on 20 July , " Avenger " drew within hailing distance of " Emerald " and received oral orders to instruct all northbound vessels to " hug the coast " because of the U - boats operating to seaward . In accordance with those orders , " Avenger " hailed a steamer at 0210 on the 20th and warned that Portland - bound vessel of her danger . " Avenger ' s " third patrol ( 22 to 24 July ) took her to waters off Atlantic City , New Jersey . When her fourth ( 26 to 28 July ) took her across Delaware Bay to Lewes , Delaware , she sported a new weapon - three depth charges . The fifth ( 29 July to 1 August ) again took her to patrol the shipping lanes off Atlantic City . At 0825 on 7 August , " Avenger " had just commenced escorting a submarine when a muffler exploded on board . The damage apparently not severe enough to force the craft to curtail her assigned tasks , " Avenger " returned to Cape May that afternoon , remaining alongside the Fish Dock there until 12 August when she got underway , at the end of a towline , bound for Essington , Pennsylvania . Docking on the 13th , " Avenger " consequently underwent repairs to her hull and engines at Essington — a spell of yard work that lasted into early October 1918 . During that time , so that her crew would not get " rusty " on their weapons , they conducted rifle and machine gun practice at the local yacht club rifle range . After her post - repair trial trip to Marcus Hook and back on 9 October , and her second ( record ) trial trip to Wilmington , Delaware , and return , " Avenger " returned briefly to Essington before moving back to her home base , Cape May , on the afternoon of 25 October . Underway the next morning , she patrolled off Cape May on the 28th and into the next day , when she was relieved on station by . " Avenger " underwent further repairs to her engines ( 30 October to 2 November ) before she departed the Fish Dock , Cape May , at 0955 on 7 November on what proved to be her last patrol of the war . She made port back at Cape May on the 9th . Her deck log for 11 November recounts the happy news received that date : " State department announces armistice signed at 5 a . m . , November 11th . " Underway for Lewes on the 14th , " Avenger " returned to Cape May on the 30th and remained there a week before returning to the Corinthian Yacht Club , Essington , Pennsylvania , on 8 December . The next morning , she touched at Fort Mifflin to unload ammunition before mooring at pier 19 , where her wireless outfit was removed and her three - pounder dismantled . Decommissioning . At noon on 19 December , Chief Boatswain ' s Mate Wunderle decommissioned " Avenger " and signed the receipt for the vessel , which was later delivered to her builder ' s yard , Clement A . Troth ' s , in Camden , where she was presumably prepared for civilian service . After that brief stint as a commissioned craft of the United States Navy , " Avenger " then served under a succession of owners , but retained her original name throughout . She disappeared from American yacht registers after 1929 .