The vast majority of detectors have no problem with being dunked, but ML has been cranking them out as fast as possible for years now. When you put 10s of thousands of anything into use, you are going to have a higher number of failures. Even a very low failure rate for all units produced could still leave 1-2,000 defective units. On top of that, you have take into account a observational bias. thousands of happy users arent making posts to say "my nox didnt drown today", but a single unhappy user is likely to post their story across many forums and groups, where more people may chime in saying "me too". Then suddenly all you see are a flood of "my nox drowned" topics.
Fair points but lets not pretend there is no problem or that they are reliably waterproof - In fact, I think that their claim of this machine being waterproof, which is of course a major selling point, borders on false advertising if not over. There have been far too many reports of water failures to dismiss the whole thing as normal attrition to be expected in any unit ,,, Though obviously its tough if not impossible to get an accurate grasp on the situation short of minelab releasing repair/return stats, which of course they will never do.
At this point, I see no reason to assume, as you, that they have a "low failure rate", absolutely not. If we are to assume, I'd assume the opposite and declare it high, certainly higher than any other hybrid water machine ever released.
Is it because they have sold alot more so there are more failures ? Once again, an assumption but I don't recall anywhere near this amount of reported failures with the AT pro, and I'm guessing they sold truckloads of those.
Really not that much to compare it to [hybrid water machines], I know 1st hand the Whites MX Sport had a slew of early water failures [I had one and got a refund after mine fried out after 5 minutes in the water] ... Far as I'm aware, they took corrective action and fixed the problem, at least mitigated it. AT pro, now we have the Simplex which I have heard a few reports of failures but not on a level that would indicate deign problems such at the Nox.
Outside of those most other [name brand] water machines are dedicated to the water, and as expected, not a whole lot of reported failures with those.