Snorkeling while on a "surface interval"

So, I was thinking:

If you were at a great dive site that was also a great snorkeling site, after swapping out your tank, what if you were to snorkel around for a while?

Technically you are not on compressed gas, so would this be a bad or dangerous thing?

Any studies on it?

Surface snorkeling shouldn't be a problem.

However, I wouldn't freedive during the SI or shortly after a SCUBA dive, all advice goes against that.

A couple of links:
http://www.scubaboard.com/forums/sn...e-diving-during-surface-interval-problem.html
Freediving After SCUBA Diving: Is It Safe? | Scuba Divers Travel Network (SDTN)

The only two issues I could see with it would be if you got caught in current or something and had to exert yourself strongly (highly discouraged after diving) or if you lost more body heat instead of rewarming.

swimmer_spe:

So, I was thinking:

If you were at a great dive site that was also a great snorkeling site, after swapping out your tank, what if you were to snorkel around for a while?

Technically you are not on compressed gas, so would this be a bad or dangerous thing?

Any studies on it?

Click to expand...

When you say a great dive site, that is ALSO a great snorkeling site....I think you are saying it is less than 30 feet deep....maybe even 15 to 20 feet deep. If this is the case, and your first dive was at this site, and you are in good aerobic shape, my expectation is that you would be just fine snorkeling this on the SI.

The likelihood for bubbling should be very low.

Personally, I have done this for 40 years on SI's on 40 to 60 foot reefs, and have never had the slightest hint of DCS. Remember the "models" ..the tables, are about how large populations will statistically be effected---and everyone assumes that they will be effected like this hypothetical "average" that is "created" and measured. There will be "Individuals" that are far less likely to get DCS from 50 minutes at 60 feet ( even from 70 minutes at 60 ft) than is predicted by the tables.....and there will be people that are fairly likely to get a bubbling and DCS related response from 50 min at 60 feet....or from snorkeling after a shallow dive..... I correlate aerobic and anaerobic fitness to this, and the related extra perfusion that is associated with peripheral adaptations to the training that causes high aerobic and anaerobic fitness---which also suggests that a very sedentary person with poor fitness, will bubble quite easily if diving at the limits of the tables.

I and others do it regularly between two dives on weekend day trips and haven't had any problems. We normally pull into a shallow bay for lunch and then do a snorkel. I'd avoid freediving and overexerting yourself. It may be an issue if it is cold but that isn't normally a problem where I dive with water temperatures between 18 and 26 deg C.

I do it when I go down to NC. There is so much life I don't even need to dive down!

We would snorkle daily in between dives. For me I'd like to swim over shallow reefs and relax and watch the show. Cold water was not an issue. Adventure-Ocean

I guess I should have said I was in Hawaii.

Depends how easily distracted you are by things on the bottom I guess. I snorkel more than I dive, and I'm constantly ducking down a few metres to check out things below. I took my girlfriend snorkelling between my own dives once, and it was pretty frustrating being stuck on the surface not allowed to free dive.

Only issue I can see is overexertion considerations due to DCS concerns, otherwise go for it. We run a competition to see who can hit certain depths on the line for a bit of fun.