For the zip lining your phone needs to be attached to you, you can't hold it loose. Other attractions depends, but of course be aware that there is a lot of water involved. In general it is good if you can attach it to your wrist.
@@Svenywhere thanks for your quick reply, we will visit tomorrow, are you talking about „just a wrist strap“ like from a Wii remote? Or a sturdy wrist/bracelet where the camera is fixed with a screw?