Okay, i'm in the part where you get the gun on the water craft and it's after you shoot down the first chopper. In the rectangular dock area. I've destroyed the Combine tank/car things and now I need to launch the watre craft off a ramp onto a deck that connects to a pipe/tunnel. When I launch the craft, it looks like it's gonna make it to the other side, and them it hits an invisible wall. Am I doing something wrong, or is this the end of the line for the craft?