Cayman Islands
The Cayman Islands certainly offer diversity without a long trip from the states.
GRAND CAYMAN
Grand Cayman has beautiful beaches and probably the most topside activities or restaurants anyone would want. There is shopping, bars to hang out in, and live music. Cathy Church has a shop at Sunset House where you can often meet her and see her beautiful underwater photos from the area. The seven mile beach area is beautiful for walking and photo opportunities. You can even make a side trip to "Hell", a small area with black volcanic rocks, a few curio shops, and an actual post office you can send mail from with a postmark from Hell. For diving, the reefs are easy to reach from many dive operators and offer a diversity of schooling fish, sponges, turtles, rays, and even sharks. The Kittiwake wreck as well as other wrecks in the close vicinity add variety and interesting structure which I really enjoyed. We were lucky enough to see the tail end of silversides on the wreck of the Balboa right in the Harbor too. StingRay City on scuba with a small group was so much fun feeding the rays. You need to protect your fingers from the eager snappers though. Grand Cayman makes a good dive vacation, but for us it was a great stop with plenty of good diving over 3 days on the way home from Cayman Brac.
CAYMAN BRAC
Cayman Brac offered multiple relaxed dive spots on reefs all along the edge of the island. As a photographer, I never lacked for subjects both wide angle and macro and anything in between. Schools of bright snappers brightened the reefs among colorful sponges. Turtles munched on big sponges with no worries about divers hanging about. My favorite were the groupers who followed us like pets. It seems the dive guides hunt the lionfish and then feed the groupers, so they joined us right away each dive. My poker stick resembled the dive guides spears, so they followed me closely and would even "show" me where the lion fish were, confused when I didn't feed them. I quickly learned that if I poked at an area with my stick, the groupers would go right there, a great tool to get them to pose right where i wanted them in my reef scenes. The boat dives were offered mostly in the mornings, and we were on our own in the afternoons. A highlight dive is the Tibbets wreck with great structure and lots of life. The shore diving was really easy to access with actual ladders or stairs and even showers at some sites. We could easily get to reefs and wrecks by ourselves from shore and take as much time as our tanks allowed. The dive boat did make the excursion across to Little Cayman's Bloody Bay wall one day which is very achievable from Cayman Brac. The amazing strawberry sponges were in abundance there. They look dark brown without light but the first time my strobes lit one up I was amazed at the super bright rich red color. They became my favorite focus on the reef. I like the idea of being able to dive off both islands while staying on one.
It is easily possible to visit all 3 of the Cayman Islands in a single dive trip and be able to enjoy the diversity they provide.