Monterey Bay National Marine Sanctuary - provides a wealth of information on the creatures and communities found within the national marine sanctuary http://bonita.mbnms.nos.noaa.gov/sitechar/bio.html
The Slug Site - plenty of info and photos of west coast nudibranchs can be found on this Web site http://slugsite.tierranet.com/
"Apex" Critters - photos and information to help fend off your non-diving friends when they start telling their "shark stories". http://www.shark.ch/home.shtml
The Marine Mammal Center is a private, nonprofit organization based in Sausalito, California that rescues, rehabilitates and releases orphaned, injured, or stranded marine mammals along a thousand mile stretch of California coastline, from Mendocino County to San Luis Obispo County, including the entire San Francisco Bay Area. The center conducts research into marine mammal health and immunology, and provides educational programs. http://www.tmmc.org/
Divers Alert Network - offers 24 hour medical advice in diving emergencies, great books on scuba diving physiology and latest research, as well as providing insurance for the scuba diver at large http://www.diversalertnetwork.org/
The Channel Islands National Marine Sanctuary - provides a wealth of information about the Channel Islands http://www.cinms.nos.noaa.gov/