Building a submarine is not that kind of a hobby.
> Casually China has the strongest and biggest (ever-expanding) aquaculture sector in the entire planet.
Yes, so they don't have much to learn from your average hobbyist sub builder.
> Militar technology is totally out of reach for they, too big, and uncloneable, but I bet that a lot of companies with fresh money to burn could find good uses for a toy like this.
https://en.wikipedia.org/wiki/Type_093_submarine
How is that for a toy? That's a nuclear powered sub the Chinese have a bunch of them, this one displaces 7000 tonnes submerged compared to the 40 tons of the Nautilus, has a crush depth orders of magnitude deeper than the Nautilus and carries a bunch of cruise missiles.
Do you honestly believe the Chinese could learn even a single useful thing from Madsen's toy?
The only people with a direct interest in running private submarines are the drug cartels and some salvage companies, and neither of those would lead to Madsen killing a journalist.
> Do you honestly believe the Chinese could learn even a single useful thing from Madsen's toy?
I honestly believe that 99% of people in China don't know how to build a submarine or have free access to militar technology so, yes I do.
But lets explore your idea. If the reason is neither the passengers, nor the submarine, must be in the cargo. "Somebody found a shipload of something illegal, thus must be 'silenced'". Is a perfectly valid hypothesis. The problem is that: 1) No drugs where found and 2) would the guy be so dumb as to invite a journalist to enter in a relatively small submarine if there was a shipload of something illegal inside? It seems unlikely to me.
There are far simpler explanations which do not involve foreign powers, secrets, drugs and so on.
If Peter Madsen turns out to be a drug smuggler on top of a murderer I guess it shouldn't surprise me but I'd put the seduction gone wrong entry a lot higher on the list of likely possibilities.
As for the 99% of the people in China, that's a nice attempt at reverse Chinese math, we're still looking at 10 million people then who know how to build a submarine? I'd be highly surprised if it was even 1% of that. The regular people in China need a submarine about as much as you or I do, which is not at all, which is one of the reasons why Madsens' efforts were notable in the first place.
Casually China has the strongest and biggest (ever-expanding) aquaculture sector in the entire planet. Militar technology is totally out of reach for they, too big, and uncloneable, but I bet that a lot of chinese (or norwegian) seafarming companies could find good uses for a toy like this.