I've had serious problems walking on such wet, slightly rotten(*) wood this weekend. It was extremely slippery even though I was wearing my hiking boots.
As soon I applied pressure onto the food standing on these battens, it slipped away.
Is there something one can do about it? Maybe a special tread on the shoes or walking technique?
*) As Aravona pointed out in the comments, this surface might not be rotten but "have a mildew, moss, type organism growing on top of it (common on decking in your garden too, it comes off with a pressure wash)."