I worked as a technical diver, not a saturation diver, with full-face comms and Nitrox and spare air, servicing underwater hydraulics/electrical systems for over 450 dives. No need for extended stays underwater or lengthy decompression. Most injuries were related to the physical labor around heavy moving machinery and tool usage. Glad to say there were few injuries and these were all minor injuries of those involved. The important technical point is that the largest increase in volume takes place in the first atmosphere or 33 ft (10 m) under the surface. The inverted bucket example of a full bucket of air going from full of air to half air at 33 ft below surface. It goes from 1/2 full of air to 1/3 at the 2-3 atm change. And that's where most typical recreational diving takes place with a maximum of 30 m to 40 m (100 ft to 130 ft). Diving in confined spaces with the surface blocked by structure or machinery, and with the occasional oil leak causing visibility of less than 24 inches due to light diffusion provided for a mix of challenging tasks while staying calm and rational. I miss that part of it all.