Though the Soviets persisted with double hull designs there are several important reasons why the west has (in general) abandoned double hull construction and favours single hull construction:

1.Cost...A single hull submarine of the same size and displacement is usually cheaper than a double hulled one (now i'm just talking about the cost of actually building the hull here...not the cost of all the systems you have to put into the hull to make it a functioning submarine).

2.If you compare the usuable internal volume of a single hulled submarine with a double hulled submarine of comparable displacement then the single hull sub will have more internal volume (more room for equipment/stores etc)A classic example of this is the Victor 3 class.In this class the soviets attempted large scale 'rafting' of the subs power plant to reduce radiated sound levels.To do this they had to substantially lengthen the sub.If they had re-designed the Victor 2 to a single hull design (keeping the length and beam the same) then they should have been able to accomodate teh 'rafting' techniques no problem.

3.Noise.The modern submarine can be said to have started with the USS Albacore.This submarine had a 'body of revolution' hull (looked like an airship).It enabled very high underwater speeds (uo to 33knts) to be obtained and improved stability comprared to the previous narrow,high speed designs.Albacore was a test submarine and in one test she measured her own self generated noise.It was found that the double hull design was fundamentally more noisey than a single hull design.The reason for this was that the thin plates that make up the outer skin of a double hull design will 'rattle' at speed.The thick (pressure) hull of a single hull design does not suffer from this defect.