[hosepipe]

Why single and not double hulled?..

Ans; BECAUSE the right torpedo will kill you just as dead.. and 2 hulled is way more expensive.. heavy.. requiring much more power to power them.. which makes more noise.. with more possible cavitation(noise).. making them glorified ANCHORS.. in a shooting war..

**Better; unmanned armed unwater vehicles like the predator except under water.. controlled by an attack sub.. or surface craft.. or BOTH...

[myknowledge]

You mean construction of double-hulled subs is simply a waste of money for lesser benefit?

With the development of hull insulation technology for the Borei class SSBN, cavitation and other machinery / hull noise will be nullified, making the sub a hard target to detect on sonar.