Why do people add a few minutes to their last deco stop?

[scubadada]

Of course they are. No one else is propagating that sort of information, and once they get an idea in their heads and have nothing to refute it, why wouldn't they repeat it?

I heard over and over as a new instructor that dehydration was the number one cause of DCS, and I repeated that misinformation to many students before I found out 1) there is no research supporting it, and 2) there is a danger in overhydrating. On the dive boats I used in Florida this winter, the DMs made the need to drink as much water as possible a key part of their initial introductory speeches. I did not tell them otherwise.

I hear this in the initial briefing in Florida all the time. I do not speak up either. I'm hoping most divers hydrate in moderation.

 

[dmaziuk]

I'd be concerned with the run-off from their suits as they climb back onboard. As if I needed more reasons to avoid Florida.

 

[MyBuddy]

2) there is a danger in overhydrating.

So what are these dangers from over hydrating as it relates to diving?

I’m aware of hyponatremia, where too many salts get flushed out through sweat and aren’t replenished by only drinking water. It’s my understanding that in an otherwise healthy individual this really only occurs in those that participate in extreme endurance activities like triathletes and marathon/ultramarathoners who may be drinking a lot of water and eating little. Which doesn’t really fit the description of most divers, even the ones who are doing very challenging dives. I don’t think your average diver in a tropical local that goes out the night before and has 2-4 beers and a plater of nachos the night before diving is at risk of being overly hydrated and depleted of salts. I think it’s far more likely that some diver sitting it the sun in a hot wetsuit and full kit finishes becoming dehydrated on the deck of a boat passes out and smashes his face. If hydrating helps stave off DCS I don’t know, seems plausible that it could help off gassing, but it certainly helps prevent heat related injuries that dive operations would also like to avoid.

I can’t say I’ve ever seen anyone suffering from hyponatremia. Though I have been present when numerous people have suffered heat injuries from heat cramps to full on heat stroke, though not specifically during diving.

 

[scubadada]

@MyBuddy

Risk factor for immersion pulmonary edema

 

[boulderjohn]

@MyBuddy

Risk factor for immersion pulmonary edema

What he said.