Learn from this diver's experience how to avoid the dangers of wearing too much weight underwater.

Groupers have been a favorite fish since the pioneering days of diving. Widespread in the tropics and subtropics, they are slow-moving, curious and intelligent, and many are highly colored. Their big eyes and rubbery lips give them a cartoonish charisma. Groupers are long-lived and can become so infatuated with divers that they follow them closely— much to the enjoyment of any shooter. Such big personalities deserve the best photographic treatment.

In this edition of Ask a Marine Biologist, Dr. David Shiffman answers questions recently sparked by a frozen shark found in Cape Cod.

Polar expedition guide Kayvon Malek gives advice on how to be a successful diver for polar cruises in locations such as Antarctica, Alaska and the Arctic.

Everything you always wanted to know about oxygen toxicity, including what's happening as well as signs and symptoms.

Alexandra Owens used to be scared of sharks—terrified actually. Once she learned to dive, the fear slowly put itself to rest. Here's her story.

Experience one of the easiest-to-dive Florida springs just outside Orlando, Florida. Affordable, shallow, and clear, there isn't a better place for a new diver to get comfortable in the water.

In this edition of Ask a Marine Biologist, Dr. David Shiffman answers one of the most-asked questions about sharks—are they mammals, fish, or something else?

Each year in the midst of a chilly Colorado winter, this group gets together to play underwater poker for charity.