Today this kind of work would be handled by ROVs (remote operated vehicles, something like: http://www.f-e-t.com/our_products_technologies/subsea-solutions/rovs

Today this kind of work would be handled by ROVs (remote operated vehicles, something like: http://www.f-e-t.com/our_products_technologies/subsea-solutions/rovs-work-class/ http://www.f-e-t.com/our_products_technologies/subsea-soluti...), which is probably for the best - the pilot sits in a comfortable room onboard a ship on the surface and interfaces with the ROV through a terminal, which is hooked up to the ROV with a very long cable (tether). I work on simulators that are used to train pilots for their upcoming jobs, which also helps to reduce mistakes, which makes this line of work a lot safer than it used to be.