This is not a site so much as a page.  It is designed to function as a start page for Scuba Divers.  It features a new Scuba Diving picture everyday.  In addition, many of the most common online dive destinations are featured as well as links to the most common internet destinations in general.

An online resource site focusing on underwater photography.  Free and paid accounts for personal photo galleries.

An online community for the scuba diving community.  Founded in April 2006.  Offers blogging, forums, an online dive resource directory, news aggregation specific to the diving community, and more.

Home page of the organization we all know and love.  Resources include certification program information, equipment tips, and links to PADI centers.

From their website:
Founded in 1996 by marine ecologist Dr. Gregor Hodgson, the Reef Check Foundation is an international non-profit organization dedicated to conservation of two ecosystems: tropical coral reefs and California rocky reefs. With headquarters in Los Angeles and volunteer teams in more than 80 countries, Reef Check works to create partnerships among community volunteers, government agencies, businesses, universities and other non-profits. Reef Check goals are to: educate the public about the value of reef ecosystems and the current crisis affecting marine life; to create a global network of volunteer teams trained in Reef Check's scientific methods who regularly monitor and report on reef health; to facilitate collaboration that produces ecologically sound and economically sustainable solutions; and to stimulate local community action to protect remaining pristine reefs and rehabilitate damaged reefs worldwide.

As stated on their site:
NAUI Worldwide is the world's oldest, most respected and second largest diver training agency in the world. Established in 1959 as a not-for-profit membership association and organized solely to support and promote Dive Safety Through Education, NAUI continues as the recognized leader in innovative education. NAUI Worldwide offers a full range of training programs from Skin Diver through Instructor Course Director, with dozens of specialty courses including Nitrox and technical diving. Thousands of member instructors, dive businesses, resorts, and service centers are located in countries throughout the world.

A global advocacy group which seeks to help protect the oceans of the world.

Scuba Show is an annual event showcasing the strength of the diving industry.  It claims to be the largest consumer dive expo in the western hemisphere.  The dates for 2007 were June 2nd & 3rd in Long Beach, CA.

The underwater lost treasures website, dedicated to all genuine treasure lovers, underwater archaeology and maritime history re-discovered.

Online Diving Shop