Dove with the folks there at the Mariott Resort in Key Largo and had a
rather pleasant experience.  Their boat was larger than  a 6pack
though.

Key Largo area has a remakable amount of cool diving.  I saw more new
animals there there in 3 dives than I'd seen in 6 or more dives on two
carrib. cruises, actually.

I'm not sure I'd recommend the operation tha truns out of Pennekamp
park.  Maybe I just had a bad experience, but I never get sick while
on Bonine, and my dive buddy and I both got very sick on their boat in
relative mild chop, and we both felt like our air tasted a little funny
when checked our regs at the beginning.   We weren't experienced
enough to demand other tanks.  Not sure if the air was why we ralphed,
but I have my suspicions.  I've been in far worse sea conditions since
on the same meds and never felt as horrible as I did that day.

Have fun!

Best Regards,
--
Todd H.  
http://www.toddh.net/

For a six-pack I'd head to Quiescence. Great outfit, been around for close
to 30 years. Best small boat operator in the upper Keys. They're at MM
103.5.

They have a website, but I don't have the URL.