Battalions (ACB). Engineering duty officer An Engineering Duty Officer (EDO) is a restricted line officer in the United States Navy, involved with the design, acquisition, construction, repair, maintenance, conversion, overhaul, and disposal of ships, submarines, aircraft carriers, and the systems installed aboard (weapons, command and control, communications, computers, etc.). As of August 1, 2016, there are approximately 835 engineering duty officers on active duty in the United States Navy, representing approximately 2 percent of its active-duty commissioned officers (and approximately 400 engineering duty officers in the Navy Reserve). Special Operations The Special Operations Warfare (SPECOPS) insignia is earned by officers by virtue of training in the Explosive Ordnance Disposal (EOD), Mine Countermeasures (MCM), Operational Diving and Salvage (ODS), and Expendable Ordnance Management (EOM). Not to be confused with Special Warfare (i.e. SEALs), Special Operations, in Navy parlance, refers to dive qualified EOD technicians. The insignia shares a similar design to the Surface Warfare insignia, but is considered a different category. Special Warfare There are two Special Warfare insignia issued to Navy personnel serving under Naval Special Warfare Command, a part of USSOCOM: Special Warfare and Special Warfare Combatant-Craft Crewman. The Special Warfare insignia (aka the "SEAL Trident" or simply "Trident"), is awarded to personnel who completed BUD/S training and qualification, and have been designated as Navy SEALs and assigned to Navy SEAL Teams or SEAL Delivery Vehicle (SDV) Teams. The insignia is the same for both officer and enlisted personnel and is one of only three breast insignia authorized for enlisted personnel that is gold in color. The Special Warfare Combatant-Craft Crewman (SWCC - pronounced "swick") insignia is awarded to enlisted personnel who complete SWCC training and qualification, and have been designated as United States Navy SWCCs assigned to Special Boat Teams. The SWCC qualification insignia consists of three separate insignias that denote the level of qualification achieved individually by SWCC sailors. The insignias include SWCC Basic, SWCC Senior, and SWCC Master. The SWCC Basic insignia is a 2-1/2 by 1-1/4 inch silver matte metal pin showing a background of a cocked flintlock pistol, a crossed naval enlisted cutlass, and a Mark V Special Operations Craft atop a bow wave. The SWCC Senior insignia incorporates an upright anchor in the background of the SWCC Basic insignia. The SWCC Master insignia incorporates a banner with three gold stars on the upper portion of the anchor from the SWCC Senior insignia. Submarine