Patent Foramen Ovale and Fitness to Dive

A PFO is a passage in the wall between the right and left atria of the heart that can be found in about 25 percent of adults. Its size and the degree of blood flow through it vary. It can greatly impact diving.

A surgeon prepares to place an occluder in the heart of a patient with a patent foramen ovale (PFO).


Do you fully understand the origins of breathing gas? Learn more about the art and science of producing breathing gas.

Man holds an oxygen tank

Return to Diving

Breast cancer can be debilitating and one DAN member shares her story of recovery and returning to diving after complex breast cancer surgery.

Female diver floats above giant yellow coral

Clams & Friends

Read one couple’s story about diving with shrimp, clams and other little critters.

A fluted giant clam has a purple piece of coral in it

Exercises to Reduce & Prevent Knee Pain

Knee aches and discomfort are a pain in the joint. With proper exercises and awareness, you can reduce and prevent knee pain to help you dive and live your best life.

Woman bends over to rest after run

Looe Key

Looe Key is considered a gem within the Florida Keys. The reef boasts corals, sharks, rays, grouper and many other species of wildlife. Learn more about diving Looe Key.

A sad-looking grouper with spotty flesh, floats over a coral reef

Marine Biogeography

Marine biodiversity is vast and each river, lake, ocean and reef has different life. But what underlies regional diversities in marine biodiversity? How can one place support more life compared to others? Learn more about this kind of biodiversity.

An outcrop of colorful coral and a diver swims in the background

Research & Outreach

DAN can help members work through difficult situations and accidents. But DAN’s research efforts can also help divers in lasting ways.

The inside of a hyperbaric chamber is padded and no one is in it.

The Logistics of Exploration

Get a deeper understanding of exploratory diving — a sometimes controversial topic. One team of divers schemed a plan to dive and explore a deep wreck. Read more about the process.

Dive team explores propeller