After such a good puzzle with the bridge, we're faced with an old-style rump of a puzzle fighting the control system. Yes, it's that nasty swing on the rope and somehow jump off at exactly the right moment that was the bane of the previous game and generally sucks in entertainment terms. What you have to do afterwards is also confusing and irritating.
i thought i'd post something on this. i'm talking about here:
You have to run and jump off the first ledge, use the rope and climb the robe (E on the pc) as quick as you can before you hit the water, then swing across and jump at exactly the right moment on the other side to get to the second ledge. You can also summersault off, I did this by accident a couple of times. I think the rope length is important. I found it easiest by having the rope as long as possible without actually being in the water.
After this there’s then the problem of what next. Obviously you can get to the pole which descends, but where to next. This is the irritating, bit because there is no game clue that you have, in fact, opened a portal below the water. I tried for ages to jump from the pole quickly before it dropped hoping to get to the ledge above. Also when you fall in the water, you have to do the first wall jump again and, no, you can’t save the game either on the second ledge, it puts you back on the first again on reload!
here's a vid: