Swimming between zones
I get what you’re saying, but they don’t have to teleport you to the exact position you would be in the next zone. Maybe have 2 or 3 designated spots along the edge of the water in the next map, and it puts you at the closest one.
There happens to be an exit which you can swim into which takes you to a neighboring region and which comes out in an underground cavern. The gate in question is in the southern end of the lake in Lornar’s Pass, so one of these does in fact exist.