Interesting assertion bundling some issues that might be useful to tease out.
1.) Absolute vs. Relative Risk. I'll illustrate by way of analogy.
In the U.S. Walmart and Target are major retailers with many locations serving legions of customers, some old, medically frail, etc... It stands to reason a number of people die shopping there through no fault of the retailer (as is also true for hotels, etc...). For sake of argument, let's say Target decided to differentiate itself by having every store employ a full-time medical crisis intervention team (e.g.: EMT, etc...), and after a couple of years, data showed your odds of dying while shopping at Walmart was now 5 times that of shopping at Target. If you previously preferred Walmart, would you switch to Target because Walmart is not frighteningly dangerous, 'outside the bell curve?'
Many of us would not. If the threat beforehand was deemed well within acceptable limits, cutting it by 80% wouldn't be compelling, particularly if the price went up.
But if the risk of shopping at Walmart were deemed too high, that would be different.
And if the risks were thought due to dangerous practices at Walmart (e.g.: frequently neglecting spills creating fall risks), that would be different.
2.) Cost-Benefit Analysis. Let's look at some possible interventions from an earlier post:
Particularly given that a number of staff likely have 1st aid training, would I be willing to pay, oh, say, another $200 for an otherwise identical trip just to have a ship environment-focused EMT (or similar) onboard? What if a 3rd option cost $500 more but you get a family physician onboard?
Sounds nice, but in the real world setting of liveaboards how much of a 'value add' is this likely to be?
Since the Conception disaster I imagine this is expected. Like the desire for a 2nd exit from confined (e.g.: below decks) staterooms, the safety argument is compelling.
So like 2 roving night watches? Now we're packing on extra staff and running up the bill.
So we're left with some basic questions:
1.) What are your odds of serious injury or death per day on a given liveaboard, or liveaboards in that category?
2.) What additional amount of money leads to what reduction in that risk?
3.) Is it worth that amount of money to cut risk that much?
I haven't seen reliable hard numbers and the decision is personal. With other things, we often do thoughtful cost-benefit consideration. How much money would it cost me to buy how much additional safety?