Blue Dragons 

These small yet magnificent mollusks live in the open ocean and are at the mercy of wind, tide, and currents. As they float upside down just beneath the surface, their blue-striped bellies point upward while their metallic backs are counter-shaded when seen from below.

Blue Dragons

Homemade Dive Gear

The “Historic Dive Helmets” article from the Second Quarter 2024 issue of Alert Diver triggered memories of my father, Burton Stewart, and his best friend Leno Prestini. In 1935 they crafted their own dive gear from a water heater, milk can, garden hoses, and Goodyear balloon material for the suits.

Prestini and Stewart preparing to dive

Used Rebreather Scrubber Disposal

Sorb, or scrubber, plays a critical role in rebreather diving, as it is responsible for removing carbon dioxide (CO2) from the diver’s breathing gas. Small granules or pellets absorb exhaled CO2 and allow oxygen to pass through. This chemical process allows rebreathers to recycle exhaled air, limiting gas consumption and allowing longer dives. 

Sorb becomes saturated with calcium carbonate after prolonged use

Rewilding Coral Reefs 

Though I believe rewilding coral reefs is a valuable approach, it requires a strong, established foundation of good old-fashioned marine conservation. I view reef rewilding as a tertiary marine conservation strategy that we should attempt only after the fundamentals of an effective marine conservation strategy (often anchored with a well-managed marine protected area) are in place. 

Nesha Ichida watches Seren, a wild leopard shark

Close-Focus Wide-Angle Photography

Most of our experiences in digital photography are somewhere between one end of a spectrum and the other. Underwater photographers often make an either/or distinction when describing how we shoot, ignoring that it is really a continuum.

Banggai cardinalfish in Lembeh, Indonesia

No Plan B

Van Morrison dropped his 34th album, Born to Sing: No Plan B, in 2012. David Fleetham, now 48 years into his career as a professional underwater photographer, reflects on that sentiment when explaining how underwater photography has subsumed his life.

manatee

Diving After a Nissen Fundoplication

I am a 57-year-old male who is planning to undergo a laparoscopic Nissen fundoplication for refractory gastroesophageal reflux disease (GERD) and a hiatal hernia. Is the procedure considered an absolute […]

stomach illustration

Diving in Remote Areas

Diving has inherent risks. The human body was not designed to be underwater, and drowning, decompression illness, barotrauma, hazardous marine life injuries, and preexisting health issues all require an emergency response. Diving in remote areas introduces additional risks, especially access to medical care.

remote destinations

A Tourniquet Saves a Diver’s Life

A recent dive trip changed the lives of everyone involved, and I hope this story might help save another life.  About 30 days before the trip, I was talking to […]

applying a tourniquet

Lung-on-a-Chip

Researchers at the University of Colorado Boulder’s Shields Lab — led by Wyatt Shields, PhD, an assistant professor of
chemical and biological engineering — are investigating how engineered microparticles, specifically designed for use in biomedicine, can be used in areas such as biosensing, where they bind to certain molecules or cells to enable drug delivery and the detection of biological conditions.

Abby Harrell diving