M. L. Buchman 
Man the Guns, My Mate [EPUB ebook] 

-a Night Stalkers romance story-
Navy Commander Deborah Reynolds pissed off Night Stalker Trisha O’Malley in Light Up the Night. As she begins her own two-year tour in command of the USS Constitution she knows her dream assignment in Boston is temporary.
Roy Wilkinson, professor of marine engineering at MIT has loved ships his whole life. Especially the day he wins a trip on the oldest commissioned ship in the U.S. Navy, Old Ironsides.
He thinks the trip is the prize, until their hearts set full sail and they both prepare to Man the Guns!