What are the conductive properties of seawater? Perhaps something along the electromagnetic field path?

I think it will be in advancing sensors... eg. using refraction of light to locate submarines, etc. Also important, IMO, will be all-electric drives for nuclear submarines that will allow power to be used more flexibly. But I am not a submariner, so take my ideas on this with a grain of salt...

Supercavitating submarines would rewrite the rules of underwater combat overnight. Imagine a vessel you could see with ease (silence is not an issue with these birds), but that no modern torpedo could possibly touch. http://www.deepangel.com/html/what_is_it_.html.

hmmmm, disagree here... If you look at the progress of RAMICs then there is an awful long way to go before supercavs can be used in a self propelled solution. You are basically looking at a need to redefine the propulsion system - before you even address the issue of submarine shape etc.. If the USN hadn't stuffed up the RAMICs IP issue and had the original inventor on board, then maybe, they would have made some progress. As it is, its not working effectively on some weapons let alone on weapons systems that are manned and internally complex.

what do you think? a sub that has a strong enough radar or sonar that is able to detect targets, at least surface one's, from a long distance; longer than what the surface assets can 'see', and also have torpedo's that have that sort of range too, plus an increased speed as you dont want to give the enemy too long to react.

An extended range torpedo would be a futile concept; as is, the modern Mk48s weigh several tonnes, a great amound of that dedicated to propulsion, and they can still only reach 50-60 MPH. The technology your thinking of already exists on Virginia and the Improved LA, via vertical launch tubes for Harpoon anti-ship missiles..

...and radars can be more powerful, able to track smaller targets / more targets etc etc but maximum range will always be decided by the height above water and the height of the target due to the earth's curved surface. At least, until someone invents some way of consistent radar refraction / reflection using the atmosphere!

hey mate, we've already done that, im sure that many other 'subsideries' will come about from this that could be applied to differing platforms. btw, im talking about the JORN radar (jindalee over the horizon; it uses the ionosphere to bounce off and pick up targets and has a massive range, we can see all of indonesia with this and most agree that this range is very conservative). ;)

JORN has a declared range of 3000+k's - which is considered to be very conservative in light of some of the anecdotal intercepts done to date. The problem with all OTH systems is a degree of range unpredictability due to the nature of the technology and mother nature. The ionosphere is a fickle mistress and can result in dramatic changes in depth. The advantage of JORN and all the other goodies that come under the aegis of Operation Dundee (which is what the US is part of) is the integration into other Australian DIGO assets and the US with its equivalents. The US has bought into participation with JORN and its Dundee "sisters" as it fills some previously big holes in its ISR systems in the region. But, OTH is not perfect.

>>The technology your thinking of already exists on Virginia and the Improved LA, via vertical launch tubes for Harpoon anti-ship missiles. *-*-*-*-* For a submariner, Harpoon is the weapon of last resort. A Harpoon launch leaves a clearly visible smoke trail which my bugmariner friends (yeah, I'm a skimmer) call "The Finger of Death". It points right to a sub's location.