Description:
You should be able to cast your ground mount while in the water. Currently, you cannot. In later expansions this was extended to flying mounts, but in WotLK it was ground mounts.
Plus: Put a ground mount and a flying mount on your actionbars. You'll notice the flying mount will be greyed out while you are swimming, but the ground mount will not.
Description: You should be able to cast your ground mount while in the water. Currently, you cannot. In later expansions this was extended to flying mounts, but in WotLK it was ground mounts.