With all that weight he'd have to be careful not to plummet down too fast or there would be compression issues. Note the two guys working the bellows almost immediately behind the chap helping the diver into the water. In England there exists a group of enthusiasts who still dive like this and offer public demonstrations of their hobby. I will see if I can locate a link to their website where there are many photos.

This is a standard diving dress type suit, quite common before the development of scuba gear. It isn't designed to swim in - indeed the weight belt and metal boots were designed to take the diver to the bottom and allow him to walk about on the bottom. Agility ceases to be an issue in those circumstances.

It's no good looking for the survivor; she already took that church organist job in Utah.

That Jules Verne diving getup looks extremely cumbersome and would make it nearly impossible to be agile at swimming, diving and searching. It does stir the imagination to visualize a giant man-eating octopus to be rearing his tentacles (I said tentacles) up out of the water very soon and devouring the poor diver who will probably never be seen again.