Using the manual routing system, you are able to perform your own weather routing. This has been used, successfully, to help sailors on many passages, world wide.
Please read the Mac version of this topic for additional information.
In the Mac section, associating a route with a vessel is described. This is done on iPhone and iPad by opening the sidebar and navigating to: Library / Routing / Vessels, and then tapping on the vessel you are working with. The vessel editor has the controls to specify which route a vessel is following.