>You are literally trying to suggest that we went from minimal usage to more than a million passengers per year in 1999 and then back to minimal usage

In the calculations I made I maintained a steady 1 million per year. Your emotions are causing you to misread what I'm writing.

>but beyond improbable and seems to be based on absolutely no logic other than 'this is what I need to try to maintain my view, so it must be reasonable.'

Slow steady growth in existing markets with bursts as they moved into new markets approximating an exponential curve, followed by low growth once all potential markets were saturated and the supply of surplus military vehicles dried up is "beyond improbable"?

I'm not making a strong claim here. I'm saying that such a growth curve is possible and not improbable.

>By contrast the assumption of normal growth is based not only.. well normalcy

Linear growth isn’t a safe default assumption. Rapid growth followed by a plateau is “normal”.

>You're not considering the possibility that your view may be incorrect in this case.

I’m almost certain you’re not actually reading what I’m writing. I’ve said numerous times that I can’t accurately estimate how many people rode DUKWs before 1999. I’m not attempting to provide accurate estimates for that time period. There could have been 50 million passengers before 1999, and there could have been less than a million. There could have been 0 fatalities before 1999 and there could have been a dozen. For both of those numbers the answer is almost certainly somewhere between those 2 extremes. Where we do not know because we don’t have the data.

We do know how many fatalities there have been since 1999, and we can make a better estimate of how many people have ridden them. We’re still not going to get very accurate data. But the data we have shows that it is likely that DUKWs over the last 20 years are substantially less safe than other boats.

>For instance you are now proposing that perhaps the number of ducks in operation declined since 1999. As you mentioned, from the writeup on the original duckboat operator, there are about 300 ducks are in operation today.

We’re talking about a blurb on a website from a tour boat operator. We don’t know what his definition of Duck is. Other amphibious passenger vehicles look very similar, and some DUKWs have been very heavily modified. I’d say that 300 is fairly safe to use as an upper limit--that’s it. Even then, take it with a grain of salt.

>The NTSB did not call for a ban on ducks.

Nope they didn't. I never said they did. They called for a ban on unmodified DUKWs..

“Require that amphibious passenger vehicle operators provide reserve buoyancy through passive means, such as watertight compartmentalization, built-in flotation, or equivalent measures, so that the vehicles will remain afloat and upright in the event of flooding, even when carrying a full complement of passengers and crew.”

“Until such time that owners provide sufficient reserve buoyancy in their amphibious passenger vehicles so that they will remain upright and afloat in a fully flooded condition (by M-02-1), require the following:...”

The second recommendation isn’t an alternative. It is a stopgap solution to be implemented immediately. Neither recommendation was ever required, and only a few operators complied with the request.

>Internally it was felt that the additional buoyancy requirement was unable to be able to be effectively implemented,

The report and the official recommendation were adopted as is though. So you only think we should take the recommendations of committees when the result is unanimous?

>and that the canopies were not a danger.

Just stop. It’s only you and me, you don’t need to lie about the report.

3 staff members asked that the report be changed to “canopies represent a grave risk to passenger safety.”

By the way. This

>199.685 trillion person hours would give an average base rate of travel of 0.016 miles per hour. Obviously you need to multiply that by the average number of occupants per vehicle, but even if you say there are 10 occupants you're looking at 0.16 miles per hour on average so it looks like you missed some decimal points.

Was completely wrong. I was on my phone and didn’t bother double checking the math. I assumed the study I found with average daily time spent in a car was wrong because it was self reported.

You’re actually the one who missed 3 decimal places. I said 199,685 million person hours. That is 200 billion miles not 200 trillion as you said. With the correct number, it’s an entirely reasonable estimate.