Supersonic submarines? Whales need not fret about colliding with them -- yet.

If you want to freak the Americans out, just write a Chinese military-technology breakthrough story -- with an appropriately sinister headline, of course -- like what Hongkong daily The South China Morning Post did (Aug 24):

SCMP, Aug 24

 http://www.scmp.com/news/china/article/1580226/shanghai-san-francisco-100-minutes-chinese-supersonic-submarine

Indeed, news media everywhere picked up the eyeball-grabbing story. Here in Singapore, TODAY seemed to have missed it but ST (Aug 25) carried the story, albeit with a less sensational headline:

Ever since the Cold War days, the US and Russia have been in a "race" and grappling with the problems of harnessing what is called "the supercavitation effect" to underwater military vessels (submarines) and weapons (torpedoes) that could enable them to reach sustained supersonic speeds while having the ability to be steered too. The experts agree that if these technical problems could be overcome, the nature of underwater warfare would have been dramatically changed. It would also be potentially "hair-trigger" destabilising; hence the SCMP headline above was being mischievous, to say the least.

What the Chinese scientists are reported to have achieved is a novel way of addressing the problem of steering (manoeuvring) a supersonic underwater craft. But no convincing evidence was provided so I suspect most defence experts elsewhere would remain sceptical. In any case, it is one thing to achieve something experimentally and then applying it to operational assets like large long-range submarines.

Importantly, too, the cat-and-mouse battle of wits between deep-diving stealthy submarines and their nemesis -- the surface and airborne anti-submarine warfare assets -- continues relentlessly. If such supersonic subs are going to be "noisy" (easily detected by sophisticated sensors) on their way across the Pacific, then they are as good as dead ducks!

So the Americans -- and leisurely swimming peace-loving whales! -- need not fret yet. A Chinese missile-armed submarine sailing stealthily from Shanghai to San Francisco in 100 minutes is still in the realm of science fiction. For that matter, a US sub sailing at such a supersonic speed in the opposition direction is still a pipe dream.

Finally, a very good article on the possibility of supercavitating supersonic submarines becoming a reality may be found in this link:

http://www.subsim.com/ssr/page33.html