In "Metal Gear Solid 2: Sons of Liberty," players take on the role of Solid Snake (and later, the ninja Raiden), who must make use of his own sneaking skills and high-tech items to take out an international group of terrorists. One of the available items, thermal goggles, allows Snake and Raiden to check for enemies by looking through walls and checking enemy bodies for dog tags. The player must find the thermal goggles in two different locations, the Tanker and the Plant.
Begin the game to find yourself on the tanker. Work your way up to the Tanker's bridge.
Open the door on the left side of the bridge to enter the Navigational Deck, where you must fight Olga. After the fight, move to the other side of the navigational deck and ascend the stairs to find a ladder. You will find the thermal goggles at the top of the ladder.
Play through the rest of the freighter mission, after which you will lose the thermal goggles and begin the Plant mission.
Get out of the water once the mission begins,and move to the right side of the pool. Dive into the water at this spot to find the thermal goggles again.