|MadSci Network: Zoology|
Well, spiders live on every continent except Antarctica and they can even live at the beach or in intertidal zones. However, no spiders actually live in the ocean.
However, there is another invertebrate that is not really a spider, though it is called the sea spider. These creatures are spiderlike with their small bodies and long legs, however, I am not aware of them biting people. These creatures feed off of soft bodied animals like sea slugs or hydra.
So, in the water you should be safe from spiders!
Elizabeth A. Mule'
Shimek, R. (2003). And Along came a spider. http://www.reefkeeping.com/issues/2003-01/rs/index.php
Scott, S. (1999) Ubipuitous sea spiders surprisingly hard to find. http://starbulletin.com/1999/02/08/news/oceanwatch.html
Try the links in the MadSci Library for more information on Zoology.