Hello, I ment, you start in level 16, your floating, you swim forward and automaticly jump onto a bleu ledge, you walk to the edge, turn around and step backwards to hang and drop from that ledge. You will fall down but you keep hanging in the ether. Turn right and swim out of the ether onto the ledge. When you stand there angle Indy to the left side near the edge of the ledge he's standing on, with his face towards the other ledge. You do Z-ctrl and Indy will rolls onto the next ledge.
It is difficult so you have to make a quicksave. If you really not know how to make it trough this difficult level go to www.gamecenter.com/Feature/Guide/Indiana/ss16.html
There you will find the complete walktrough of level 16 (and all the others). It is clear written language (even for me!). For me the beginning of this level was also a big problem but with this walktrough you will play the game. If there are any more questions, I hear you. Succes.