The Diving Area (level 5 I think)
Climb the stairs and do a running jump to grab the opposite ladder. Climb up and press the switch to turnthe fan off at the bottom of the pool to stop you from getting sucked in. Swim down through the tunnel past the fan to pick up some greandes and then pull the lever in the water to open a door nearby. Climb up the nearby ledge and shoot the dog and 2 gurads (1 of them carries an uzi!) Jump to the other side of the pool if you can using the platforms but avoiding the hooks. If you fall you can return back to the ledge via the underwater tunnel.
Go through to the room with a slope and some green oil ? which is dangerous (if you slide down backwards and hold X you can grab the ledge and pick up the 1st secret) Slide down the middle and at the last point jump to get to the other side. Walk round to the left and climb the ladder all the way to the top and drop off to the right and then follow the passage to see a hole in the floor. Walk round to the left of it and jump down it backwards and hold X to grab the ledge, let go and then press X again to grab the ledge below. Climb up and shoot the guard. To the left there is a hole in the fence where you can do a running jump to grab the blue card.
Walk to the passage and follow it round to get to the long ladder again and climb up and then go down the hole in the floor as before and on the pathway go right and use the pass card.
When you enter shoot the dogs and stay well back from the flame thrower guy since you will get toasted by him. Head round to the opposite doorway and open the outside door. Go down the stairs and shoot the guard by the pool. Push the crate to reveal a panel. Jump into the water and enter the tuinnel and then lure the diver out and shoot him from the ledge which you had jumped in from.
Swim back through the tunnel and pull the lever which will open a very close gate which you will need to swim through and pull another lever and then swim round to the right and surface.
Return up the stairs to the large hallway with the doors. Go through the door to your left and go up the stairs and shoot the 3 guards (you can't stop the helicopter from taking off) go through to the next room and flick the right switch to temporaly turn off the fire so quickly run through and fall down the trapdoor and pick up the 'M16' and return back to the same room before the fire restarts.
Flick the switch again and then the left switch and run down the corridor jumping over the trapdoor to collect the machine chip, roll around and quickly escape before the fire relights.
I will continue this walkthrough later on
E-Mail if you would like some Cheats for Tomb Raider 2 (I haven't put them up here because it will ruin the game otherwise for people who aren't totally stuck)