Evidence for example of visual surveillance of submarines (sister comment reply) in form that are usually used as narco submarines, with no victim coming forward for their rarer occasional use (tourism or science).

Someone has pointed out gold, people smugglers, and fisherman could be explanations but I don't think such submarine is suitable for much but the gold smuggling case there.

It is suspicious, that is all. Most time these form of submarine are used, it is to transport narcotics. Coast Guard has boarded many of them, this almost always the case.

Is it proof they are guilty beyond reasonable doubt? No

Do I think they deserve to die based on evidence? No

Hell, I'm not arguing we should even do anything about it.

If my cousin Niko was spotted on one, I would have questions, because it's suspicious. I wouldn't conclude he needs executed.

board the vessels, arrest the sailors, produce the drugs. that’s the just way. this is just a prelude to invasion and/or regime change so US capital can grab the oil. (I assume you agree based on your comment)