Is there more of a difference other than the addition of nautical terms and spatial concepts stuff?
Check the ASTB section.
Thoroughly.
My experience mirrors a lot of what's been said. If you've only dealt with enlisted recruiters before, then dealing with ORs is a whole 'nother ball game. I'm in the early phases of getting my packet together. Finding an OR was a pain. Getting them on the phone, or to return a phone call, is worse.
These are busy people. Be persistent. Also, from what I've heard, ORs make their nut off SWO and Nuke guys. A BDCP candidate is fairly low on list of prospects. Similarly, my OR was very honest about how difficult it would be to get an Intel slot. SNA or SNFO applicants face a similar uphill battle. They'll do it, but don't expect too much enthusiasm on their part unless you're extremely well qualified. It's a numbers game.
Call and leave brief, cogent messages stating who you are and what you want. Be polite and friendly. And carry your own ball! Do as much research online as you can. It seemed to help my recruiter take me seriously when, after bouncing back and forth on a few topics, I had a lot of information he wasn't really expecting. Help them help you.