Dolomedes spiders, also known as Dock spiders, are incredible swimmers that are often found living near the shores of lakes and ponds near cottage areas.
This is their prime habitat where they are able to hunt for insects, tadpoles, minnows and other various small aquatic creatures that may float by. Dock spiders hunt for their prey by feeling vibrations in the water instead of spinning a typical web.
These spiders hold little to no threat to humans. They produce a venom which is used when hunting their prey, but are otherwise very calm unless they feel threatened themselves.
As you can see, this momma was holding her silken egg sac using her front fangs and she will do so until the babies are ready to hatch. Once hatched, she will stand guard of her young until they are ready to venture off and live a life of solitude.
One of these egg sacs can produce up to as many as 1000 babies which can be quite nerve wrecking but at least they help keep the mosquito population down.