I'd think you can take it in Key Largo since that's where REEF HQ is.
I took it in Cozumel over the course of two evenings and a morning two-tank dive trip. On the first evening, we spent two hours with the local REEF field coordinator who taught us to ID the 100 most common fish seen in Coz (she knew that we already knew a lot of the species so she increased the scope of the course from 50 to 100.) Before this, we didn't know the ID keys or families. For each fish we learned the family and species, many via fun & very memorable sayings like French grunts have "French designer stripes" and "Look for the button on the Mutton" Snapper. She also gave us information about diet, habitat and behavior so that we'd know where to look for which fish. At the end of the evening, she told us about REEF surveying and explained how to conduct a survey.
We went out the next morning and took surveys on two dives. During each dive, the instructor would point to fish at random and ask us to show her the name on our survey sheet. She also showed us additional species if an interesting one swam by.
That evening, we went back to the classroom to transfer our survey data to a scan-able form to mail to REEF for their database. Afterward, we took an easy quiz on what we had learned, which qualified us as "Novice Level 2" REEF surveyors. While no one was interested in buying the PIC, the course qualified us all for PADI Underwater Naturalist certification cards.
The best part about the course was obtaining a foundation on which to build knowledge -- to know with some confidence which family a fish is probably in and which families it definitely isn't (really cuts down the time needed to browse that Fish ID book!) The course was fun and the possibilities for seeing additional species are endless!
