S-3 underway, date and location unknown, but probably mid 1920's. The slit in the forward superstructure is for the retracted port bow diving plane. Directly above this on the deck are the three Y-tube sonar hydrophone "rats". The heavy wire running from the jackstaff on the bow, up to the periscope shears, and down to the flagstaff on the stern is a mine clearance cable. There is a thinner cable also attached to the jackstaff, running up to the fully raised radio mast and down to the aft flagstaff. This is a radio aerial wire for long range communications.
S-4 mooring up to another submarine in Pearl Harbor, Territory of Hawaii, circa May 15, 1921. She was reported to be making active operations at Pearl Harbor on that date being referenced in the logbook of the USS Celtic (AF-2), a refrigerated stores ship. The Celtic reported passing the S-4 exiting Pearl Harbor as the Celtic was entering the harbor on that date.
Several auxiliary Mine Warfare vessels can be seen in the background. One is most likely to be the USS Lapwing (AM-1), engaged in mine sweeping operations in Hawaiian waters from January 1921 until she decommissioned April 11, 1922. The other is most likely the USS Oriole (AM-7), who was also decommissioned in 1922 on May 3rd. Both were decommissioned due to the Washington Treaty terms.
The S-4 sailed with SubDiv 12, and SubDiv 18 from Portsmouth, NH for Cavite in the Philippines on November 18, 1920 and arrived, via the Panama Canal, at Pearl Harbor on April 15, 1921. They departed Pearl Harbor on November 3, 1921 for Cavite, arriving December 1, 1921.
