AOW + Nitrox should be adequate for most recreational dives.
Some operators will insist deep Specialty if deeper than 30m.
+1
I've never had a dive shop asking for Deep specialty cert personally.
AOW+Nitrox for now, potentially Solo at some point in the future if you tend to travel alone (no perma dive buddy

Keep in mind even if that dive shop will take you on the boat with just OW cert, that may limit dive site selection for the whole boat (makes many divers not too happy...)