Stay with me on this... I'm not a huge fan of big spiders. In Costa Rica I was introduced (at a distance) to a Golden Orb spider who's web was at least 15' across. This lady isn't that big, but she's big enough. I'm impressed I got close enough to take the picture actually.
It's all very well knowing that this is a dock spider, also called a Fishing Spider, and that while they are big, and hairy, and a little scary looking, and while they can move very quickly, they are not aggressive, nor is their bite poisonous to humans (although it can cause a reaction... so the trick is to ensure they're not in a threatened position where they might feel the need to bite you.) Knowing in your head is one thing, reaching right down beside her with the camera is another.
But I did get the photo, and Charles and Andrea got at least as close as I did with their camera, too. Fishing spiders are actually amazingly cool. First of all, they can actually fish.
Holding onto docks or vegetation with their back legs, they trail their front legs onto the water's surface, feeling for vibrations. In effect, the entire lake surface becomes their 'web', and they are able to discern between a fish rising to the top, an insect splashing into the water, or a leaf falling from a tree. Which, to be honest, is more than I can do...
Having located the source of the vibration, the spider then 'runs' across the water to grab dinner. These spiders can also move around under the water -- encased in their own little silvery coating of air that helps them breathe.
The female carries her egg sac with her until the babies are ready to hatch. You can see this big bag carefully held in one of her mandibles. The babies will hatch out looking like little tiny spiders, and will then swarm up onto her abdomen until they are big enough to go out on their own. Not such good news for the male spider -- the females of this species can and do eat them after mating. When the little ones are ready to move on, however, move on they do... with a vengeance. While large spiders have to walk from place to place (or hitch a ride in the boat, like this one is doing), little spiders can fly.
Well, not actually fly... not with wings, but small spiders are very light. They can spin out some silk into a nice breeze, and then be wafted aloft. It's called "ballooning" and this is the time of year you see it happen, in the autumn, when the air seems to fill with gossamer strands and drifting seeds. Some of those are spiders off to see the world.