Core-stuff in my opinion:
Small town where ON? - I just met an instructor from Georgetown on my Blackbeard's trip.
- Nitrox -
- Deep - trains you for full Rec depth limit, familiarity with redundant gas sources.
- Navigation - everyone need to know this and practice unless you are always diving with a guide.
- Night - some of my favorite dives are night. It can be off-putting in the beginning, and frankly, does have a higher risk profile than the same dive in the light.
- Where you are - Drysuit if you are diving local.
- Search and Recovery is fun and is good for getting you comfortable with task loading and team skills (Less fun when viz drops below arm-length)
- Wreck - if you want to go on them - Reel skills are good to have. (I am literally one dive from the checkoff on this - I actually aborted part way through because I realized I WOULD get stuck in my twinset - and now my instructor has been out of the water for some issues.)
Small town where ON? - I just met an instructor from Georgetown on my Blackbeard's trip.