What are some tips for keeping an updated resume without committing OpSec violations or divulging too much for potential future employers?

You need to think in terms of how a future civilian employer will think. Outside some obscure government job that you might apply for that has specific need to know about your missions, most don't really care. They don't care that you were responsible for maintaining the electronic tracking of ninjas during operation "Aquaman's Spear" at xxx deg lat, yyy deg long.

They want to know that you have experience maintaining data links, or communications equipment, or general troubleshooting of electronic systems. I suggest you go to the internet and look up the general open source description of your job (rating?) and use that to guide your resume. Also talk about more general skills and accomplishments that you may have.

I don't know the specifics with the Navy, but the Army has transition resources that can help and often provide specialists in taking your military career and pulling out stuff that is useful in a civilian resume.

Unless you spent a career in JSOC most of what we have done is unclassified, at least from an infantry point of view. Best rule of thumb is to keep things simple. Instead of "deployed on presence patrol/checkpoint security mission in Nasiriyah, IRAQ" Just say "deployed to Iraq" In fact employers appreciate simplicity when it comes to military applications as a majority have no clue what we would be talking about if we laid our entire ERB out on paper. Speak to what leadership positions you held and how much responsibility you had, and not so much what you did.

I am a bit curious about this. As an E3 how much could you have been exposed too that is classified and what of this classified material would you put into a resume. Have you signed a Non-Disclosure Statement? If you did then you are limited as to what you could say. I have worked in the intel world a bit. Even with that in my background I would now talk abou it. It was years ago and it really wasn't anything special. Where I was in Iraq 14 years ago isn't going to compromise anything. What I have seen is some people overact when it comes to this. Plus, you would really have to question if telling anything from operations to a future employer would mean anything. Would a civilian really know what any of these means. If in doubt I would seek out a military resume writing assistant.