R-15 through R-20
The USS R-15 seen in the Panama Canal. The date is September 1918 thru December 1918 when she and her sisters R-16, R-17 and R-18 patroled Panamanian waters in the closing months of WW I.
She is backing away from either a pier or maybe a tender. The exact location is in some doubt but the area seems to fit the Rio Chagres vicinity with the rail lines in the background and pairs of power poles as a clue.
The WW I time frame is pretty certain due to the fact she is armed with the 3"/23 (the gun barrel is mixed in with the legs of the two chiefs in front of the conning tower) caliber retracting deck gun which she carried for only a short time. After her return from Panama she and her sisters went to Mare Island to have them removed and get deck modifications to accept the new 4"/50 gun she will receive once she reported to Pearl Harbor.
See More R-15 photos
R-16 (SS-93)
R-17 (SS-94)
R-18 (SS-95)
R-19 (SS-96)
R-20 (SS-97)