Item description:

Pick up the Empty Air Bottles leaning against the wall with the hanging clothes,
and then shift the clothes on the rack around until you find the Diving Suit
Finally, pick up the Diving Helmet on the other side (beside changing room)
Now you need to fill up the bottles with air
Zoom in on the mechanism to your left and place the bottles under it
Zoom out and then zoom in on the panel to the left, which indicates the air pressure
Turn the knob on the top right until it reaches 180, then press the green button
The device will start shaking as it fills up the bottles
Zoom in on the tanks again and pull the grey handle down, followed by the red lever
on the left (also down). Give it a second, and then pull the adjacent lever on the right.
Your bottles should now be full. Go inside the changing room and Kate will put on the diving suit

She will now walk underwater.

!! AS You Will Notice Playing To Here, There IS An AutoSave Point Here. I Did Create A Back Up Save,
But When I Tested It, Kate Couldn't Pick Up The Large Cog And Square Key On The Ground At The Hatch !!

From where you start, proceed right (Hold R2 to run)
Stick to the wall so you don't get lost. You'll come to a gate type thing (hatch)
Pick up the Large Cog and Square Key on the ground and then zoom in on the gate
Pick up the Stacked Gearwheel and Cog underneath it. Place the Large Cog on the left knob,
the Gearwheel on the center knob, and the regular Cog on the right knob
Go right again and then toward the back until you reach another metal hatch on your left
Place the Square Key in the hole underneath the wheel and turn it right
The hatch should open slightly
Open it fully, manually, and then turn the wheel to the left as far as possible
Pull the lever on the left down. This will open one of the locks

Proceed through the new opening until you find the wreckage of a boat,
and pick up the Chain in front of it
Now return through the opened lock and run towards the screen to get back to the other lock
Place the chain you found on it and then turn the wheel as far right as you can, then pull the lever

Cutscene of Kate opening the Dock Gates and meeting up with Capt. Obo
***** "20,000 Leagues Under The Lake" **** trophy pops

You'll be at a police checkpoint
Look inside the right window of the police checkpoint building
to see how Cantin's been getting on since we outsmarted him.
***** "Turning The Tables" **** trophy pops