Just got back from Provo, did some nice diving there.
Its all wall dives, and good for nitrox enthusiasts - but it isnt challenging from a navigation point of view! Swim along the wall against the tide, swim back with it.
There are plenty of big things to see, reef sharks, big turtles, eagle rays, southern sting rays, big groupers. Also lots of naughty lionfish, who are eating up the smaller reef fish - including, sadly, lots of fairy bassetts...!
You wont see huge shoals of fish or spectacular coral gardens.
The water is so clear, with amazing viz which makes it great for filming and taking great pix.
The view from the boat on the way out to the dive sites is spectacular. Almost neon turquoise water as far as the eye can see. Its shallow and over sand, so it is spectacular. Pretty often you have dolphins swim alongside the boat too.
I dived with Dive Provo. Great gear, great boats, very safety conscious, fun staff. We dived off West Caicos several times... overshadowed by unfinished luxury developments thanks to the collapse of Lehman Brothers. I also dived out on Molasses Reef and French Cay, a day before I went there were whales sharks there... I missed them :-( Didnt even see a shark there, sniff.
If you make it out to Salt Cay, you may be lucky to dive with Humpbacks.
Have fun! And if you are on Provo - make sure you eat at Mango Reef and Coco Bistro!