I never thought of that Jeff but if you set up a program as proposed with a thousand fishing boats you would be able to automate a large part of the recording and mimicking of the 056's. A thousand boat program might be as expensive as twice a hundred boat program. And routing the decoys can also be automated. If a submarine hears ten identical ships around it and knows only one is dangerous, but not which one, what should it do?
I'm not convinced it will be useful, but technology is always improving so who knows?
If you ever want to utilize fishing trawlers as anti-submarine naval auxiliaries, it's more efficient and economical to use them as ad-hoc "area denial" thru deployment of trawler nets, using them as decoys to attempt to fool hostile subs will simply a fool's errand, nothing more.
Also, acoustic signature factors in a lot of things, including hull size, engine's type and age and conditions, the screws it uses; most Chinese fishing trawlers are about the size of the 037 series boats or the 032 series, 056 is almost twice their length, to say the very least.
It's a matter of physics for me.
If your science teacher and economics teacher heard of your crackpot idea, even just a tenth of it, they will be vomiting blood immediately and might die 24 hours later due to sheer guilt and a sense of failure. If I forwarded your "idea" on Facebook you'll be the laughing stock of the year, generate tons of "like" for me at your expense.
It's not just science that says its improbable, the economic aspects of it makes it completely unworthy - for all the effort getting wasted on it, might be better spent on building more 056 and expand the helicopter fleet, the latter is the weakest link in PLAN's arsenal.
