Yep. Chinese have done it again. :-)

[gmx95]

Soon we will all travel underwater in a supersonic submarine.

https://au.news.yahoo.com/thewest/a/24825330/shanghai-to-san-francisco-in-two-hours-via-supersonic-submarine/

[DrG]

And yet it sometimes takes me 45 minutes to drive 8.3 miles to work here in Los Angeles.  Maybe I can hope for underground tunneling...

[Watoshi-Dimobuto]

That is more than 3000 kilometers per hour. I doubt they can do it. They haven't created a plane that fly that speed. What will happen if there is a big fish that suddenly block the way of the sub travelling at 3000km/hour. Submarine are created for stealth, fast submarines would be more noticeable from above.