Depth to Time Ratios

[JasonWelbourne]

Last year right around winter I invested in a dive logger which I am just now getting to use. Mostly I do Free Immersion and Constant Weight w/o fins when I go diving. Last year was my first year, and I spent most of it learning basic skills and glipmsing at the possibilities of further training. So now I have a few dives under my belt this year and fortunately I was able to record this @ a resolution of 1 second.

So here is what I want to know. I analyzed all of my dives and produced three numbers from them.

1) D/Tt = [Depth in feet] / [Total Dive Duration in Seconds]
2) D/Td = [Depth in feet] / [Descent Duration in Seconds]
3) D/Ta = [Depth in feet] / [Ascent Duration in Seconds]

So for instance, the dive for which the profile is attached was a Constant Weight w/o fins. It was done just swimming free, not near a line or anything and wasn't much of a strain. I was wearing a cheap 3/2 with no weight. These were the numbers that I got out of it

1) 0.8209
2) 1.3415
3) 2.1154

Now, I know that changing one's boyancy properties would alter 2 and 3 in a predictable way, but within certain limits would probably not affect 1 very much. So that being said, what is the ideal balance between 2 and 3 for dives of varying depths and styles and also, for any situation involving a sufficiently deep dive, how high can training and circumstances be expected to reasonably raise 1?

 

[JasonWelbourne]

Does any one else that does CNF have some dive profiles that they could post?

 

[fpernett]

Also a recreational no fins dive

Descent 0,64 meters/seg
Ascent 0,90 meters/seg
Depth/Total Dive 0,37

 

[DeepThought]

Amusing, it seems it is actually possible to see both of your strokes (some of them) in the graph (small horizontal lines - staying in place).

 

[Walrus]

I used to think that when I first looked at my no-fins dives, it almost looked like I sunk a little on every stroke.
What's really happening is the D3 is mounted on the wrist, and what happens to your arms on a no-fins dive....... ?

 

[kingohyes]

Aha, it moves up and down similar to your ARM movements

 

[subaquaticus]

Last year right around winter I invested in a dive logger which I am just now getting to use. Mostly I do Free Immersion and Constant Weight w/o fins when I go diving. Last year was my first year, and I spent most of it learning basic skills and glipmsing at the possibilities of further training. So now I have a few dives under my belt this year and fortunately I was able to record this @ a resolution of 1 second.

So here is what I want to know. I analyzed all of my dives and produced three numbers from them.

1) D/Tt = [Depth in feet] / [Total Dive Duration in Seconds]
2) D/Td = [Depth in feet] / [Descent Duration in Seconds]
3) D/Ta = [Depth in feet] / [Ascent Duration in Seconds]

So for instance, the dive for which the profile is attached was a Constant Weight w/o fins. It was done just swimming free, not near a line or anything and wasn't much of a strain. I was wearing a cheap 3/2 with no weight. These were the numbers that I got out of it

1) 0.8209
2) 1.3415
3) 2.1154

Now, I know that changing one's boyancy properties would alter 2 and 3 in a predictable way, but within certain limits would probably not affect 1 very much. So that being said, what is the ideal balance between 2 and 3 for dives of varying depths and styles and also, for any situation involving a sufficiently deep dive, how high can training and circumstances be expected to reasonably raise 1?

my first comp in constant weight :

depth : 84 ft

dive time : 54"

descent time : 23"

remaining at the bottom : 4 s

ascent time : 27"

1. D/Tt = 1.6

2. D/Td = 3.7

3. D/Ta = 3.1

 

[JasonWelbourne]

FYI, I usually mount my dive logger on my hand in the watch position via a hairband. Sometimes though I put it in my weight belt. Might do that instead next visit.
Subaquaticus - That is a pretty awesome D/Tt. You didn't specify so I figured I would verify that it was done w/o fins. Also, how were you weighted. I think I am going to try for something over 20m this weekend, and am curious about weighting myself for it.

 

[subaquaticus]

Subaquaticus - That is a pretty awesome D/Tt. You didn't specify so I figured I would verify that it was done w/o fins. Also, how were you weighted. I think I am going to try for something over 20m this weekend, and am curious about weighting myself for it.

Could you give some more explanations ? Why is it "awesome" ?

You juggle with figures ; it would be wiser to give some technical and physical interpretations...

Up to now my experience of constant weight is quite low ; in terms of compensation I feel kind of wall at about 26 m (84 ft) ; since I have plenty of air in my lungs for the trip, I do not need to go quickly ; then I go as slowly as possible to be comfortable with my ears....

 

[subaquaticus]

Last year right around winter I invested in a dive logger which I am just now getting to use. Mostly I do Free Immersion and Constant Weight w/o fins when I go diving. Last year was my first year, and I spent most of it learning basic skills and glipmsing at the possibilities of further training. So now I have a few dives under my belt this year and fortunately I was able to record this @ a resolution of 1 second.

So here is what I want to know. I analyzed all of my dives and produced three numbers from them.

1) D/Tt = [Depth in feet] / [Total Dive Duration in Seconds]
2) D/Td = [Depth in feet] / [Descent Duration in Seconds]
3) D/Ta = [Depth in feet] / [Ascent Duration in Seconds]

So for instance, the dive for which the profile is attached was a Constant Weight w/o fins. It was done just swimming free, not near a line or anything and wasn't much of a strain. I was wearing a cheap 3/2 with no weight. These were the numbers that I got out of it

1) 0.8209
2) 1.3415
3) 2.1154

Now, I know that changing one's boyancy properties would alter 2 and 3 in a predictable way, but within certain limits would probably not affect 1 very much. So that being said, what is the ideal balance between 2 and 3 for dives of varying depths and styles and also, for any situation involving a sufficiently deep dive, how high can training and circumstances be expected to reasonably raise 1?

I think the majority of DB members use the metric system... i.e. :

meters instead of feet ;
meters per second instead of feet per minutes ;
degrees Celsius instead of degrees Fahrenheit...

the figures you give are homogeneous with the inverse of a speed...

if you give a depth in feet, you should give a time in minutes in order to be coherent with your own unit system..

you should give in your post in order to make it clear :

1. the depth reached....

2. the total duration of the dive....

 

[DeepThought]

Yeah Jason, you have some scientific orientation. Use the SI system.
(KMS - Kg, Meters, Seconds) (French originated AFAIK)

 

[subaquaticus]

Yeah Jason, you have some scientific orientation. Use the SI system.
(KMS - Kg, Meters, Seconds) (French originated AFAIK)

Many airplane crashes may be explained by a confusion between the metric system and the "Imperial" British system...

In all cockpits there are double indications, some time even 3 (the speed can be given in km/hour, in knots - nautic miles per hour - and in miles - non nautic ! - per hour...

As an example, the crash of an Airbus A320 in France received following explanation ; the landing slope of an airplane is normally 3° in metric system (the full circle is 360°), which corresponds with a rate of descent of 600 ft/minutes in the British system (it is supposed then a nominal horizontal speed) ...

The pilot made a confusion reading on the wrong scale : he read 3 thinking it was 3 degrees ; in fact it was 3000 ft/mn, which was 5 times the normal slope...

Please do not make freediving more complicate than piloting an airplane...

 

[JasonWelbourne]

I am just looking for data. I think in metric but my american friends don't, and my dive logger defaults to feet which is how my post wound up being made regarding feet. But come on guys, let's not argue over dogma. I just wanted to start a thread to collect the relevant data. The reason I said it was awesome is because it was by far the highest total dive depth to time ratio I have seen so far in this data collection process.

Based on the current results I do not anticipate many more responses within the time frame I had in mind, so I hadn't really thought about organizing the process, but if someone was so inclined all that is needed is
" [Depth in meters] / [Total Dive Time] / [Descent] / [Ascent] "

 

[immerlustig]

for cw with bifins my averages are:

0.8-0.85 m/s descent
0.87-0.92 m/s ascent
ca 3 s for the turnaround

roland

 

[JasonWelbourne]

Went diving again today, but alone this week so I didn't weight myself or venture too deep. Instead I tried to improve my form a bit, and it resulted in some better numbers...

63 seconds / 57 feet = 18.5m / 36 seconds / 27 seconds

which comes out to

0.29 m/s total dive
0.51 m/s descent
0.69 m/s ascent

a little better than last week.

 

[DeepThought]

Jason, did you check at what depth approx you are neutrally buoyant?

 

[JasonWelbourne]

No. I need to do that, but there seems to be such a large window in which I barely move at all once I come to rest. Makes it hard to tell without spending considerable energy trying to measure it. I need to invent a neutral bouyancy alarm.

 

[DeepThought]

Use a rope man.