Great Barrier Reef, Galapagos and Hawaii...
very nice, but not cheap for those who live Europe...
I recommend southern Egypt: There are a lot of bays with sea grass.
On 1 dive with a max. depth of -8 m I saw a least 12 turtles (pictures tomorrow).
In addition you can see there sometimes dugongs (sea cows) and around the deep water reefs some pelagics.
MANUEL
