We use one trigonometric function to determine the hit angle and deduct the amount transferred as angular velocity and add the force to right direction.   It's a really nice suggestion that I like, I don't know how animating "choppy oceanic water", it would require to implement a terrain-dependent bonus or effects, then adding the force would be easy now. However i like it, not sure about what would be the timeline to even have the features enabling this.

That effect is really well done, did you use a trigonometric function to obtain its positioning, or am I just, as usual, overthinking? I was thinking, if the game has some choppy oceanic waters at some point, that could become handy. Besides, that could give different advantages to ships, since Mediterranean ships weren’t ocean-going, unlike northern Celtic ones.

When I saw this, it raised a real question for me! 

What I would like to say is that I think the Warring States would fit the campaign mode for China at that time (they have different general leaders and units, but basically follow the Han structures), since apart from special units, leaders, etc., I don't think there would be many differences from the Han for a separate civ with new structures and units, though of course I could be wrong.

@Perzival12Try it now https://github.com/0ADMods/civ_grid