I don't know about 'top professional photographers' but read on.....
I've just finished running an underwater photo course for professional scientific divers. The learning curve involved in using new techniques is so vastly improved by the use of digital that I can honestly say that the same course content would have been IMPOSSIBLE in the same time frame shooting film. The quality of results at the end of the course was so good, using 5Ds and similar, that it undoubtedly bettered anything that could have been shot on film given the conditions. Not everyone aspires to be a 'top professional' but for people who need to take underwater images, digital can be a revelation.
I'm sure that film isn't quite dead for some applications, but underwater it is almost certainly now moving into its death throes. I don't own a film camera any longer and have absolutely no desire to do so. I've said this before and I'll no doubt say it again, underwater digital results can now exceed those from film.
Nice Hasselblad outfit John, but you might find it hard to find a dealer keen on taking it in.