Nope sorry, it's terrorist related. Has to be. The government has us all on 'interest watch'. What this amounts to is that if anything is doing anything even remotely out of the ordinary, interesting, etc. by default they must be 'terrorists' and reported to the 'proper authorities'. Invention? New ideas? Without alerting the government?!? Are you mad?
I imagine even when it's proven not to be terrorist related beyond all shadow of a doubt (which it isn't), instead of expressing interest at the ingenuity of these three submariners, some will still call for them to be charged with a trumped up charge.
So much for freedom, we'd rather be safe....