I noticed quite a few players fall into the canal and drown. The easiest way out is to simply teleport to starting town. To do so, open your character window (C by default or doubleclick your stamina bars) and in the lower left, rightclick teh body icon and select the Capital Teleport option.
If You find yourself a bit further away from the starter town and don't want to use the teleport option, there is also an ability available from the body menu, called Last Grasp. Use Last Grasp when you are out of stamina but close to the shore. Last Grasp activates the Climbing Mode even when you are out of stamina and lets you climb out of the water onto the shore. It won't last forever so don't try to climb a mountain.