After returning to New York City on 30 April, she resumed type training off Block Island and in New England coastal waters.

[1] The merchant steamer City of Rome spotted a single white masthead light but was unable to determine its course, speed, or intentions.

The courts found City of Rome at fault for not reducing her speed when in doubt as to the movement of S-51 and for not signaling her change of course.

The United States Navy argued that it was not practicable to have submarines of this class comply with the letter of the law and that, as a special type of warship, S-51 was under no legal compulsion to do so.

S-51 was raised on 5 July 1926 by a team led by then-Lieutenant Commander Edward Ellsberg with Lieutenant Henry Hartley assisting (both reached the rank of Rear Admiral).

[3] She was struck from the Naval Vessel Register on 27 January 1930 and sold for scrap on 23 June to the Borough Metal Company of Brooklyn, New York.