[1.0.0.56] Settler captured in shallow water becomes unmovable

[BBInMass]

I used a galley to capture an enemy settler in shallow water. After I captured the settler, I am not able to move it.
In the image below in the spoiler you can see the stuck settler, he has movement points but can not move.

Spoiler screen shot :

 

[Leyrann]

Have you researched the tech you require for Settlers to embark?