Dive into one of the tanks and
swim through tunnel.
and Thigh pads
Go all the way up and
look for the green tunnel
from which you can dive
in one the the tanks.
Instead of going into that
tunnel go straight forward
and jump on top of the
water-tunnel.
Go to the rocketlauncher
(the one upstairs), use the
translocator to get on top
of the almost hidden plateau.
There you'll find your sniper-
rifle and ammo (and some health).
