This is a raft spider video.
Translated from Natuurgek blog in The Netherlands:
In the Waterloop forest, part of the Voorst forest, a population has been discovered of the raft spider.
This is the first time that raft spiders have been found in Flevoland province.
That this rare spider is present shows that the water quality in the Waterloopbos is excellent.
The raft spider is on the international red list of endangered animal species.
Fossil spider from age of dinosaurs in Canada: here.