I remember this, it must be nearing 4 years since the inception of this project. I feel qualified to help, given I eventually finished working on Dark Sea 2 which is a really long, hard, but polished spiritual successor to AUA.
I must inquire what your intentions for this project are, though, beyond the fact that it's another underwater adventure. How difficult, long, or dissimilar to the original will it be? Trying to inject plot into it or keep it rather plotless? Etc.