There are canal stops as seen in the previous tutorial but there are also docks you can build on coasts.
To build a dock on a coast, use a dock tool in the boat's toolbar and click on a coast where you want to build the dock : (it's possible to build several docks next to each other)
Just place the schedule's stop in front of the dock to make boats stop there :Somes industries appear off shore, a boat station is created with, you just have to place the stop on the industry :
Next tutorial : Airports