Case Summaries

Free-flow led to emergency ascent

A diver made a rapid ascent but, later, wondered if it was necessary.


I was diving at a depth of 60 ffw (18 mfw) in 39°F (4°C) fresh water when my regulator began to free flow. I could not stop it so I retrieved my alternate second-stage and had trouble getting it in my mouth. I surfaced quickly and thawed the primary regulator; descended again to 25 ffw (8 mfw) and made a 3 minute safety stop. After the dive, I discussed this incident with a divemaster and realized that I should have left the primary in my mouth and ascended slowly.


A sudden free-flow can be alarming but breathing from a free-flowing regulator is a skill taught to open water divers and should not normally require a rapid ascent to the surface. Fortunately this diver did not hold his breath during the ascent and was soon able to return to depth for a safety stop.

~ Peter Buzzacott, MPH, PhD