i think, it's client-side only, but anyway:
1. start to mount.
2. when you are almost mounted,disable your internet-connection.
3. jump into the water.
4. enable your internet-connection.
(emotes like /sit or /dance don't work ;_; )
/edit: look, what happens, when you jump, or swim back-/forwards. this effect stays until you press left or right on your keyboard (you can use your mouse). this works also on land
1. start to mount.
2. when you are almost mounted,disable your internet-connection.
3. jump into the water.
4. enable your internet-connection.
(emotes like /sit or /dance don't work ;_; )
/edit: look, what happens, when you jump, or swim back-/forwards. this effect stays until you press left or right on your keyboard (you can use your mouse). this works also on land