Supersonic submarine.

[ZenOps]

Old article, but it seems much closer to reality.

http://www.dailymail.co.uk/sciencetech/article-2734072/Shaghai-San-Francisco-100-minutes-China-reveals-plans-supersonic-submarine-using-underwater-bubble-help-swim-faster.html

Seems that gases do not need to be ejected from the front of the vessel. If the submarine can generate enough power, it can superheat the tip and basically vaporize the water in front of it.

[ExtraSlow]

Probably will be used for sprints to evade torpedos.

[revelations]

Theyve had 40 years to perfect this ....

[Ca_Silvia13]

We will have people living on Mars before this breaks the under water sound barrier lol

[Darell_n]

Sound in water is nearly 5x that in air. Good luck with that. Need to exceed 5335 km/hr.