what does dd stand for in the navy
Hull classification symbol It is important to understand that hull number letter prefixes are not acronyms, and should not be carelessly treated as abbreviations of ship type classifications. Thus, "DD" does not stand for anything more than "Destroyer". "SS" simply means "Submarine". And "FF" is the post-1975 type code for "Frigate."[6]
Recruit Training Command, Great Lakes, Illinois RTC Great Lakes is also commonly referred to as boot camp and recruit training, or RTC. Since the BRAC-directed closures of Recruit Training Commands in Orlando, Florida in 1994 and San Diego, California in 1993, RTC Great Lakes has been the only enlisted basic training location in the U.S. Navy and has been called "The Quarterdeck of the Navy" since it was first utilized in July 1911.