Found this while trolling the NPC website:
http://www.public.navy.mil/bupers-npc/boards/activedutyofficer/Documents/FY-16%20COMPETENCY%20SKILLS.pdf
It gives details on all skills promotion boards are looking for. For example, under the Language section:
Officers who have demonstrated or gained competence through assignments requiring foreign language, regional, and cultural expertise provide a unique combination of specialized skills and operational experience to support current and future Navy and Department of Defense requirements. This capability is essential for developing cooperative relationships with emerging partners which, in turn, enable successful theater engagement, security cooperation, and support of Maritime Strategy. Particular emphasis should be given to officers who have current demonstrated listening, reading, and speaking proficiency, defined as minimum test scores of 2L/2R/l+S or greater on the Defense Language Proficiency Test (DLPT} and Oral Proficiency Interview (OPI) in the following languages: Russian; Turkish; Chinese (Mandarin); Hindi; Indonesian; Japanese; Korean; Arabic (all dialects); Persian-Iranian (Farsi); Persian-Afghan (Dari); and Urdu.
It's good to have the details, as too many mentors can't/won't go into them. This document should help when you're looking for areas that you can invest time in.
