Loran-C Development.
   (Contributed by Earl Adams.)
A single reference, "A History of Coast Guard Aviation: Coming of Age (1957-1975)", reports that Bowditch and Dutton were involved in the evaluation of the prototype radio navigation system that would become Loran-C  ( http://uscgaviationhistory.aoptero.org/history03.html ). This project would have been conducted soon after their conversion to Oceanographic Survey Ships, probably ca. early 1959.  The timing is uncertain, since Bowditch is reported to have completed her conversion on 30 Sep 1958 and Dutton on 16 Nov 1958, but here is the relevant text :

" By the early 1950s, the Department of Defense required a highly accurate long range radio navigation capability. The Sperry Company had proposed a navigation system which would use phase comparison and operated on two frequencies. This was later reduced to one frequency and the Air Force tried to adapt it for tactical needs but had given up on it. The system was known as Cytac. Capt Peter V. Colmar USCG saw the value in the system as a long range precision navigation system. He convinced the Navy to fund a test using the CG Cutter Androscoggin which showed it would work. A test chain was set up on the East Coast and the Navy Survey Ships USNS Bowditch and USNS Dutton conducted a controlled survey test out as far as Bermuda. This convinced Admiral Hyman G. Rickover, father of the nuclear submarine, to go operational with it. He fought for money, got it, and Capt Loren “Zeke” Brunner USCG drove the effort and the system would become known as Loran C. The Coast Guard was up and operational in a year and a half during which time Sperry designed and built the equipment. Lcdr. Al Manning, who had been assigned to oversee equipment design, inspection and delivery flew out with the final pieces of equipment on December 28,1958. The Mediterranean Loran C Chain was up and operational nine months later. The Norwegian Sea Chain was commenced in late March of 1960. Loran C operates in the 90khz – 110khz band. Under Coast Guard operation provided a repeatable accuracy of 18 – 90 meters with a 99.7% availability factor. "