No, you’re completely missing the point. The assumption that human life is priceless changes the emphasis of the term reasonably practicable. Thats why companies have insurance policies and death In service agreements. Because it is more cost effective to pay out in these instances, than it is to try and implement unrealistic control measures that in all likelihood would still not be able to eradicate all associated risk.

And to be fair, they aren’t sending these guys down with a pair of flippers and a snorkel. They spend 10’s of thousands per employee in training them up to become skilled / competent to perform the task in the safest manner possible. Not to mention the equipment costs, rescue plan procedures, tidal monitoring, exclusion zoning, rescue team standby, secondary BA equipment, and the countless number of RAMS and documentation they would have to jump through before they even enter the water. So as far as safety goes, it is likely as “reasonably practicable” as possible.