On a recent hike I saw a spider that was so large I initially thought it was a toad or a snake moving in the periphery of my sight. I think the spider was the species Dolomedes vittatus Walckenaer, 1837 (Pisauridae), which are semi aquatic and have hydrophobic hairs that allow them to run across the water. They eat insects and sometimes, if they are large enough, will prey on vertebrates like tadpoles and fish. Unfortunately we didn’t get to see this particular one on the hunt, but it was massive enough that I wouldn’t be surprised if it was feeding on the small fish in the adjacent stream!
I don’t remember these spiders on any local outings before (granted, I haven’t been looking for them), but I’ll definitely be keeping an eye out in the future.