shohebshaikh,
My partner just came back from doing four highly successful hydro dam inspections in South America. One item you must consider is the water visibility. In low vis situations (less than 2 meters) a sonar is going to an essential tool for you to use. He used a BlueView 2-D imaging sonar for navigation and inspection. He then flew to the area that needed inspecting (mostly trash racks) visually.
He used a VideoRay ProIIIXE GTO. It was all checked in as airline luggage which eliminated the hassles of shipping gear someplace. Send me a PM if you want more information on it.
Chief
