For what it's worth, the cutaway diagram
of the sub at the top of the page at the
following web page looks alot like that
sub I took a picture of near Puerto Rico
last year. Mainly, the 'overhand' on the
back of the conning tower, and the
configurations of the 'tail surfaces'
in a cruciform<?> shape.
The url is:
http://www.kockums.se/