Free diving mixed with SCUBA?

[daniel1948]

Thanks for this information. I was going to ask this, too, but searched and found this thread.

I have been snorkeling far longer than diving, and I enjoy both and especially love free diving. On my second (and most recent) dive trip a DM told me not to free dive on a scuba trip, but another clarified: Don't scuba and free dive on the same day.

I appreciate the posts on this thread explaining the reasons for this. Based on these explanations, I presume it would be safe to free dive before snorkeling? Say, perhaps, skip the first dive of the day and go snorkeling and free diving, and then begin diving with the second dive of the day? (And of course do no more free diving that day.)

Daniel

 

[Dr Deco]

Hi:

Free diving before SCUBA is OK but do remember that you do gain a little nitrogen in the tissues. So, be prudent.

 

[daniel1948]

Hi:

Free diving before SCUBA is OK but do remember that you do gain a little nitrogen in the tissues. So, be prudent.

Sounds like good advice. Thanks.

Daniel

 

[pescador775]

Hi Jumpinghorse :

When "Ask Dr Deco" began in fall of 2000, this was one of the first questions.

I replied that, I believed it was a bad idea. Eight years later, I still believe that it is a bad idea. One responder even commented that he knew people who got DCS from this activity.


Dr Deco :doctor:

That was me; in 1999, I made a tank dive to 100 feet immediately after a stint of freediving to depths of 40-60 feet for four hours. After spending a week in hospital I took a more sober look at the subject of nitrogen, and roughly calculated my deco status (letter code) prior to the tank dive. It was enough to cause a problem, at least theoretically. Even so, if I were using a conservative method during the SCUBA dive, including "safety stop", I probably would have avoided any problem. In fact, I was using a Scubapro, mechanical DCP which allows quite a bit more time down than the new, electronic calculators and, as mentioned, made a slow but steady ascent without stopping. However, the proximate cause may be more mundane. Due to vigorous, sustained deep breathing and the effects of chilling on the blood and urinary system, freediving is very dehydrating. I believe this was a contributing cause of the bends, eg, dehydration. Even though I was diving in tropical waters, I got very chilled during the SCUBA phase as well which is thought to be a factor in DCS.

As to freediving between SCUBA dives, provided that the dives are no deeper than 30 feet and the diver gets plenty of water intake before SCUBA, I see nothing wrong with it. The exercise probably blows off more nitrogen than is taken up by the diver, especially if a current is running.

 

[daniel1948]

I'm not the OP. The OP was talking about free diving during surface intervals. And Pescador was talking about free diving immediately before scuba diving.

For my part, I was considering free diving instead of the first scuba dive of the day, then taking the surface interval with everyone else, and then doing my first scuba dive with the group when they do their second.

Based on what folks have posted, it sounds as though I'd be okay doing this, as long as I don't push the NDL. I'd have some residual nitrogen, but not very much, especially as the deepest I've ever gotten free diving was 45 feet, and as soon as I got there I had to come back up for air, and it takes me a while to catch my breath for the next dive.