[Skybird]

Conventional boats not beeing a deterrant.

That's the first time and hopefully the last time I hear that. One such conventional boat would be able to hold up a wholew fleet - by just spreading the rumour that it is somewhere around while being much harder to be found than an SSN or SSBN.

Of course, SSBNs have another type deterring potential than a SSN or SS. But that is true for all SLBM and ICBM-typed weapons if you compare them to conventional weapons.

If you are a CBG commander, you cannot afford to take the risk to lead your fleet through waters where you have reason to assume a modern SS is operating. If you stumble over it, chances are you will not learn of its presence before your capital ships have blown up. An SSN you could possibly detect even when it sits still, the cooling water pumps must always work. An modern Swedish, Dutch or German SS is like a drop of water in the seawater.

If that massive limitation of operational freedom is not a deterrant, then I do not know what the term means.

Only when you manage to detect it, the role of the sub is spoiled, for it cannot relocate as fast as SSNs and so the victim can race away.