Expire? You were carded NACD Intro and CDS Basic? Unless something recently changed, these certs shouldn't expire. I was diving at the intro level for over a year before I went on. Now perhaps you got a NACD doubles waiver and perhaps that expires but the CDS recently changed their intro/basic cert to allow the use of doubles at the intro level without such a waiver. Didn't think there was a expiration on it. Don't think there would be any reason to rush to go to apprentice and full as long as you are happy with sixths (there's a lot of cave to see on sixths). Might want to double check on Deco Stop but AFAIK the only expiring certification is apprentice.
Yeah, I was certed basic/intro for both NACD and NSS. I just remember him telling me that they expired after 6 months, so I'd need to progress by that time. I might have misunderstood, so I'll look into that. I, too, was under the impression that your Apprentice only lasted for about a year before you had to jump to Full, but you could stay at Basic/Intro as long as you were cozy.
I'm perfectly content with sixthes right now and getting more dives under the belt (although if what Andrew says is true about Aerolito, I might need thirds to go back and see some of that cooler stuff he's talking about).
Btw, will your wife be joining you on a FL trip or was cavern not really her thing?
She had a bit of anxiety at first, especially b/c of the halocline and going down into an overhead, in unfamiliar territory, but once she was down there, she did pretty great. She enjoyed it, I just don't know how committed she is to the 13 hour drive like I would be just to get a few weekend dives in