heres a seemingly obvious question (or not)

[Mush Martin]

What is the longest submarine in the world?

one of my janes books lists the DeltaIII sub K-433
as being involved in active underwater research
with an extension plug put in of 164 ft

that would bring her overall length to approx. 689ft.
or so at a guess.

Ive been unable to confirm this anywhere does anybody
have anything on this.

if so she would be longer than a typhoon by roughly 126 ft.

Is that right ??? lets find out.
my reference is in this case

"Janes submarines war beneath the waves"
'from 1776 to the present day'
by Robert Hutchinson
from Harper and Collins.