Surface Interval tables for Freediving

[freediver48]

Hi,

Does anyone have a source for surface interval tables for freediving, there are rumours that there may be some from Spain?

I generally let my body be my guide. The minimum that I would ever do is about 2:1, or as Jon mentioned in a previous thread,
two surface minutes for every bottom minute. This is not much of an interval, unless you are really fresh. Yesterday I dove for about 21/2 hours, and monitored what I was doing. Initially, it was 2:1, or 3:1, however as I started to get tired it increased to about 6:1. Also toward the end my bottom time was dropping like a rock, which speaks to my lack of fitness.

In Cuba, spearos hunt two miles offshore, no boat, in deep water. Even if they catch the out going tide, hunt, and catch 50lb groupers, then come home with the return tide, they have been in the water for a long time. I bet they don't have trouble with being too heavy to fit into their suits.

Best wishes,

Freediver48

 

[Jon]

FREEDIVER Magazine issue number 10 has an article about it. They even have what looks to be a set of tables inside.
It basically shows that as you increase your surface interval you decrease your nitrogen load. It seems that if you have at least a 5 minute surface interval between deep dives (100') you reduce the problems. For dives to 120' it shows different nitrogen levels dependng on if you stayed up for 1,2,4,5 or 10 minutes. THe longer you stay up, the shallower your equivalent depth on the tables are.
I am not too sure if I related that clearly. You should be able to order a back copy of the Magazine to get a set.
It looks like they applied the same "equivalent depth" theory that we use with nitrox to a regular dive table. Surface intervals seem to be the variable instead of 02.
I hope that this helps a little.
Jon

 

[JMD]

Jon,

Where can I order Freediver magazine, do they have a website or could you post their address? I'm new to this and wasn't aware that a magazine of that type existed.

Thanks in advance and safe diving.

 

[Stephan Whelan]

Howard and the Apnea Monkeys

JMD,

Howard Jones runs Freediver (can be found at http://www.freediver.co.uk) and he has almost singlehandedly brought the Freediving community to the UK. His magazine, Freediver is the official AIDA magazine and is a good buy...head on over to their website and click on "shop" to purchase a subscription and back-order copies.

 

[Stephan Whelan]

Article obtained

Everyone,

I've just finished speaking with Howard from Freediver UK and we have permission to re-publish the Freediving Tables and associated articles from Freediver issue 10.

We will have them up on the site within the week.

 

[Angus]

Way to go!

Thanks Stephan, Way to go on this important subject and extend our thanks to Freediver UK as well. Angus

 

[freediver48]

Hey Stephen,

Great going, Its good to see a this level of communications between URLs. This is a very important and I fear underconsidered issue. It really hit the other day as I watched the bubbles comming out of my mask as I surfaced and the smallest bubbles as they disappeared below me. Meanwhile the old adage came back to me about ascent speed in scuba, how could this not result in nitrogen loading.

Thanks for the hook-up, and best wishes,

Freediver48

 

[Stephan Whelan]

Delay in article

Everyone, just thought i'd inform you about the progress on getting the article on Deeper Blue.

There is a slight delay in getting the tables article as Freediver UK doesn't have a copy of it available for us. I am in the process of contacting the original author for a copy.

I'll keep you informed.

 

[Stephan Whelan]

Article available

Right, the DCI and Freediving article with associated tables are now up on the site.

Goto:
http://www.deeperblue.net/content/2001/freediving/dciandfreediving/1.shtml

To read the article by Peter Sheard. Excellent read.

 

[Angus]

What about altitude

Thanks Stephen, that is a great article. I wish I could write so well. Valuable stuff. Fortunately, I have little to fear at this time of DCI based on what I read. There is no way on this planet that I will dive to 30-40m for 19-20 minutes with only 1 minute surface time. But it does raise the question for many as they increase their recovery capacity in response to increase gas tolerances and start going deep for longer periods and then make rapid ascents. They could get into trouble. I am also assuming that these tables were developed at sea level which also needs to be factored in. Much of my diving is done above 5000 fmsl which probably serves to increase the amount of surface time necessary for nitrogen to equalize to the ambient atmospheric pressure or decrease the depth necessary to produce DCI under the surface time interval. Is this thinking correct or am I misunderstanding something? Angus

 

[Stephan Whelan]

Fair comments

Angus,

The thing to remember with any article is DCI is still more arcane art than science, so everything needs to be taken with a pinch of salt....people still don't know what long term effects of exposure to nitrogen loading in Scuba will do to the human body.

As far as i'm aware the tables were built for sea level and are not "official" so should be used as a guideline only.

I am trying to get in contact with leading DCI researchers here in the UK to continue our series of looking at Freediving and DCI, but it's slow going.

Any further information you have i'm sure will be gladly received in the forums!

 

[efattah]

Deeper DCS tables

I hope you can get some deeper DCS tables. While training for the constant weight record, a few weeks ago I made a 71m dive (2:38), and then upon surfacing I wanted to repeat the depth. I had no idea how long to wait on the surface, so I waited 14 minutes before going down to 71m again (2:21). I felt a little weird after, probably more from extreme cold than anything else. Still, it would be nice to at least have a guideline. I don't think depth tables are linear, so it's hard to extrapolate from the shallow table. It would be nice to have some tables down to 130m for variable weight training too. My friend Kirk Krack got freediving DCS after three scooter dives to 45m, 45m, 78m. Then again, his ascent rate with the scooter is suicidal!

Eric Fattah
BC, Canada

 

[Kirk Krack]

Freediver48,

Dr. Batle of Spain developed a set of freediving surface interval tables to avoid arterial gas embolism. They have a number of depth vs time SI (surface intervals) to follow. For example a dive to 30m / 100 feet with a total dive time of 1:40 should have a SI of 3:20 before another freedive should be attempted. To make it even easier the following basic rule applies:

< 25m your SI should be double your bottom time (surface to surface)

>25m your SI should be 8 minutes+

I follow these rules deligently having been the unfortunate person to have experienced this problem while deep scooter freediving (65m+).

All my surface intervals when doing warm-up dives (free immersion or constant) allow a 5:00 SI for N2 and O2/CO2 reasons. You have to be fresh and ready to roll to be effective and avoid problems.

Sincerely

Kirk Krack