The tunnel vision you'll experience through the
pod's portholes makes this process difficult. Go down
the hatch by the engine room to the pod. There are
two levers to the upper left; move the right one to
close the hatch, then the left one to release the
pod. Turn right and move the ballast lever to the
right, next to what looks like a fire extinguisher. Now
navigate around the wreck using the direction
selector and throttle below the main window.

You first need a hard-to-find, heavy hook. You
start at the stern. Move around to find the bow and
an open cannon hatch. Then move forward over the
wreck. If you're in the right place an animation will show
you in position over a hatch in the deck. Click the
ballast lever to drop into the wreck, turn twice (180
degrees), and you'll be facing that hard-to-see hook.
Now open the pod arm controls by moving the first lever
to the right of the main window. Move the arm to the
hook. This may take some trial and error. We raised
the arm slightly and were successful.

This skull will help you locate the
safe
Now, move the ballast to float up, then move to
the stern. Look for a pile of scattered timbers and
move forward; if you are face to face with a skull,
you're in the right place. Turn twice, move the
ballast lever, then turn left to see a safe. Move a
timber away from it, then turn left and place the
hook on a circular fitting. We moved the arm up a bit
and to the left before we made the connection. If you
get it right, an animation will show another timber
moving away from the safe. Move the arm to the safe
handle, then retrieve the Ion Cannon firing mechanism.

Once back in the submarine, go through the
start-up procedure (skipping the ballast portion) and
click on the center navigation point (the Island
Fortress) on the map in the sphere. Press enter on
the keypad, return to the controls and move the
throttle.