MV Foremost was constructed in 1924 by Marine Ways at Seattle, Washington, for Andrew Peterson for use as halibut-fishing vessel.

[1] On 11 December 1941, the United States Navy acquired Foremost for World War II service as a yard patrol boat.

[1] On 8 July 1942, a Royal Canadian Air Force Bristol Bolingbroke maritime patrol aircraft of No.

McLane then dropped two depth charges, after which the vessels reported that oil, bubbles, and what appeared to be rock wool (used to deaden sounds in submarines) rose to the surface.

[2] The commanding officers of the two vessels — Lieutenant Neils P. Thomsen, USCG, of YP-251 and Lieutenant Ralph Burns, USCG, of McLane — received the Legion of Merit for the action,[3] and in 1947 the Joint Army-Navy Assessment Committee identified the sunken submarine as the Japanese submarine Ro-32.

[4][note 1] After the conclusion of World War II in August 1945, YP-251 was stricken from the Naval Vessel Register on 24 October 1945.