What's the job title of the people you see on TV excavating shipwreck sites a recovering artifacts for museum?

Question

and other stuff

Answer 1

They're called salvagers.

A marine archeologist investigates shipwrecks and other articles in the water, such as collapsed bridges, cars, trains, etc.

Salvagers recover the cargo, the ship itself and anything of value.

Marine archeologists check to make certain what-ever is in the water doesn't pose a health risk and/or is not hazardous to other water craft.

Answer 2

Variously, wreck or salvage divers or marine archaeologists.