ascent rates

david_1 · June 6th, 2007, 04:44 PM

been reading on net today lots of stuff out there some I understand alot I dont. But most talk about ascent rates.

ascending from 21 to 20 meters in one min is easy to work out, but 10 meters a min is a litle harder. so what is the best practice for doing this in the green with no refrance. Is it just a feeling that this speed will get you there the right time and then an opps that was too slow or too fast.

dive guages computers do any show your ascent rate in meters/feet per min, I know they all show depth so can be worked out !

David

**neilh** · June 6th, 2007, 04:55 PM

Quote: (Originally Posted by david_1)

so what is the best practice for doing this in the green with no refrance. Is it just a feeling that this speed will get you there the right time and then an opps that was too slow or too fast.

Good question - we were wrestling with this on the weekend trying to do 9M/min, but just couldn't get the speed right. Personally I was doing this by checking the depth and time at the start and tracking depth/time as we ascended. You know where 9 (or 10) meters up is so you can tell whether you've got there within the minute or not.

I also believe that you can go slightly faster provided you pause at your target depth for the rest of the minute - but I'm not 100% confident on this! (E.g. 18M -> 9M in 30s, then wait for 30s). It could be that this is ok for 3M/min or 1M/min rates but a bit dodgy for anything faster...

Quote: (Originally Posted by david_1)

dive guages computers do any show your ascent rate in meters/feet per min, I know they all show depth so can be worked out !

Some do - check the manual for what the display shows.

I know the uwatec BT shows the rate, but I seem to remember it has a number of permitted ascent rates based on depth(?) and the rate indicator shows the % of the permitted rate - so it's not that easy to use for fixed rates!

jluttichau · June 6th, 2007, 05:07 PM

Quote: (Originally Posted by david_1)

ascending from 21 to 20 meters in one min is easy to work out, but 10 meters a min is a litle harder. so what is the best practice for doing this in the green with no refrance. Is it just a feeling that this speed will get you there the right time and then an opps that was too slow or too fast.

The way i do it is to say that if i have to ascend from 40m to 30m at 10m pr. min. i just tell myself to get to 35m within 30secs if i'm a little too fast i pause a moment at 35m and if i'm too slow i hurry up.. and then 30secs to get to 30m. If you feel that you're way off you can break it into a few more stops, maybe divide the 10m into 3 segements of 3m and then you know you have about 20secs pr. 3m but this means you have a stopwatch or maybe an aladin tec that shows seconds.

Hope this helps.

Cheers
Jonas

Devon Rob · June 6th, 2007, 05:39 PM

Hi David,
as Neil and Jonas say, break the depth and time into manageable chunks.
Don´t try to "catch up fast" if you get a little behind but keep the whole thing smooth and under control.
Get a little ahead, just stop or slow down.
Don´t get sucked in to staring at your guage.
I needed a long time to develop a "feel" for my Ascent rate and it varies depending on vis, water colour, particles, available light etc.
It´s also a skill that for me needs constant refreshing after even the shortest dry time.
HTH
Devon Rob

Quote: (Originally Posted by neilh)

E.g. 18M -> 9M in 30s, then wait for 30s

I´d try not to get into the habit of sprint then stop... stops

Gene_Hobbs · June 6th, 2007, 08:34 PM

Quote: (Originally Posted by david_1)

been reading on net today...

This statement always scares me and reminds me of a presentation from Simon Mitchell. Someone started a question with, "I read this on the internet" so Simon pulled up the Bristol Stool Chart (attached) as an example of the quality of information on the internet. Some of the information is watered down with almost no content and other information is hard and compact but there is not much of it. No real point to this, just what I thought of when I started reading this thread.

Anyway... Information on ascent rates...

Lang, M.A. and G.H. Egstrom (eds.). 1990. Proceedings of the AAUS Biomechanics of Safe Ascents Workshop. Woods Hole, MA. 220p. RRR ID: 4241

Many other abstracts and papers were available when searching the Repository for "Ascents".

Devon Rob · June 6th, 2007, 09:36 PM

Quote: (Originally Posted by Gene_Hobbs)

Some of the information is watered down with almost no content and other information is hard and compact but there is not much of it

Jan Willem · June 6th, 2007, 09:46 PM

Some bottom timers have a timer which shows the dive time in minutes and seconds. This timer can be reset at any moment during the dive (of course the total dive time will always be visible in minutes at a different place on the screen).

So if you start your ascent reset the timer and control your speed to 10m/min by checking that the timer counts 6 seconds for each meter you ascent.

Monitoring the depth and time simultaneously can be a bit awkward and it helps if you just check the depth and count to 6 (mentally) for every meter you ascent. And in addition to this, check the timer a few times during the ascent as an extra check (say for every 5 meters 30 seconds should have passed). A nice thing about this method is you can read the total ascent time when you surface.

Although I think at the end of the day one should be able to 'feel' if the ascent rate is right or not. And just use the bottom timer to make corrections.

So this is what I do, any comments?

Divingniknaks · June 6th, 2007, 11:59 PM

Quote: (Originally Posted by david_1)

dive guages computers do any show your ascent rate in meters/feet per min, I know they all show depth so can be worked out !

David

Suunto Vyper (and others) have the graphical 10m/mins representation, but I guess you want a numeric rather than graphical display if I read you right ?

It warns you if you're faster and does at least show if you're slower.

Just a thought.

GLOC · June 7th, 2007, 12:27 AM

I used to use the beeping noise on the Vyper, when it went off it was 10m/min.

Now I use the methods detailed above, try to work out time in the column and adjust ascent rate accordingly.

Regards

david_1 · June 7th, 2007, 02:07 PM

Quote: (Originally Posted by Gene_Hobbs)

been reading on net today...
This statement always scares me

well if I came along and confessed to be an expert because I had read something,I must be right :-).

we all read stuff on the net (your reading this) I have few good answers here to my question, but not what I wanted. I hoped some one would say go buy this comp put it in this mode it will then show you your accent rate in plain meter per min.

why we accend at a set rate for diffrent parts of the ascent is whole diffrent question. :-)

but thanks all even if a scared you on the way here :-)

David

June 6th, 2007, 04:44 PM	#1 (permalink)
david_1(Offline) New Member Join Date: Jul 2006 Location: sussex Posts: 295	ascent rates been reading on net today lots of stuff out there some I understand alot I dont. But most talk about ascent rates. ascending from 21 to 20 meters in one min is easy to work out, but 10 meters a min is a litle harder. so what is the best practice for doing this in the green with no refrance. Is it just a feeling that this speed will get you there the right time and then an opps that was too slow or too fast. dive guages computers do any show your ascent rate in meters/feet per min, I know they all show depth so can be worked out ! David

June 6th, 2007, 05:39 PM	#4 (permalink)
Devon Rob(Offline) Can´t remember-member Breakout Champion! Pacman Champion! Join Date: Mar 2006 Location: Lyme Bay.Devon.UK formerly Hamburg, Ger. Posts: 316	Hi David, as Neil and Jonas say, break the depth and time into manageable chunks. Don´t try to "catch up fast" if you get a little behind but keep the whole thing smooth and under control. Get a little ahead, just stop or slow down. Don´t get sucked in to staring at your guage. I needed a long time to develop a "feel" for my Ascent rate and it varies depending on vis, water colour, particles, available light etc. It´s also a skill that for me needs constant refreshing after even the shortest dry time. HTH Devon Rob Quote: (Originally Posted by neilh) E.g. 18M -> 9M in 30s, then wait for 30s I´d try not to get into the habit of sprint then stop... stops __________________ this mail was checked for viruses,worms & bad breath

June 6th, 2007, 09:36 PM	#6 (permalink)
Devon Rob(Offline) Can´t remember-member Breakout Champion! Pacman Champion! Join Date: Mar 2006 Location: Lyme Bay.Devon.UK formerly Hamburg, Ger. Posts: 316	Quote: (Originally Posted by Gene_Hobbs) Some of the information is watered down with almost no content and other information is hard and compact but there is not much of it __________________ this mail was checked for viruses,worms & bad breath

June 6th, 2007, 11:59 PM	#8 (permalink)
Divingniknaks(Offline) Resident purveyor of shiney kit.... Join Date: Nov 2005 Location: Midlands UK Posts: 1,038	Quote: (Originally Posted by david_1) dive guages computers do any show your ascent rate in meters/feet per min, I know they all show depth so can be worked out ! David Suunto Vyper (and others) have the graphical 10m/mins representation, but I guess you want a numeric rather than graphical display if I read you right ? It warns you if you're faster and does at least show if you're slower. Just a thought. __________________ Phill ----------------------------- Salvo Lights, DirZone Gear , Frog Wings Dive ? http://www.divingniknaks.com

June 7th, 2007, 12:27 AM	#9 (permalink)
GLOC (Online) Moderator Join Date: Nov 2005 Location: Fleet, Hants Posts: 1,950	I used to use the beeping noise on the Vyper, when it went off it was 10m/min. Now I use the methods detailed above, try to work out time in the column and adjust ascent rate accordingly. Regards __________________ Gareth Images of Life Photography DIR Team Foxturd Travels Underwater and Further Afar If you don't have the time to do something right, where are you going to find the time to fix it? - Stephen King

June 6th, 2007, 04:55 PM	#2 (permalink)
neilh (Online) Haemoglobin on the bus... Join Date: Nov 2005 Location: Barnsley, UK Posts: 1,900	Quote: (Originally Posted by david_1) so what is the best practice for doing this in the green with no refrance. Is it just a feeling that this speed will get you there the right time and then an opps that was too slow or too fast. Good question - we were wrestling with this on the weekend trying to do 9M/min, but just couldn't get the speed right. Personally I was doing this by checking the depth and time at the start and tracking depth/time as we ascended. You know where 9 (or 10) meters up is so you can tell whether you've got there within the minute or not. I also believe that you can go slightly faster provided you pause at your target depth for the rest of the minute - but I'm not 100% confident on this! (E.g. 18M -> 9M in 30s, then wait for 30s). It could be that this is ok for 3M/min or 1M/min rates but a bit dodgy for anything faster... Quote: (Originally Posted by david_1) dive guages computers do any show your ascent rate in meters/feet per min, I know they all show depth so can be worked out ! Some do - check the manual for what the display shows. I know the uwatec BT shows the rate, but I seem to remember it has a number of permitted ascent rates based on depth(?) and the rate indicator shows the % of the permitted rate - so it's not that easy to use for fixed rates!

June 6th, 2007, 05:07 PM	#3 (permalink)
jluttichau(Offline) Custom User Title Join Date: Nov 2005 Location: Denmark Posts: 437	Quote: (Originally Posted by david_1) ascending from 21 to 20 meters in one min is easy to work out, but 10 meters a min is a litle harder. so what is the best practice for doing this in the green with no refrance. Is it just a feeling that this speed will get you there the right time and then an opps that was too slow or too fast. The way i do it is to say that if i have to ascend from 40m to 30m at 10m pr. min. i just tell myself to get to 35m within 30secs if i'm a little too fast i pause a moment at 35m and if i'm too slow i hurry up.. and then 30secs to get to 30m. If you feel that you're way off you can break it into a few more stops, maybe divide the 10m into 3 segements of 3m and then you know you have about 20secs pr. 3m but this means you have a stopwatch or maybe an aladin tec that shows seconds. Hope this helps. Cheers Jonas

June 6th, 2007, 09:46 PM	#7 (permalink)
Jan Willem(Offline) New Member Join Date: Jan 2006 Location: the Netherlands Posts: 3	Some bottom timers have a timer which shows the dive time in minutes and seconds. This timer can be reset at any moment during the dive (of course the total dive time will always be visible in minutes at a different place on the screen). So if you start your ascent reset the timer and control your speed to 10m/min by checking that the timer counts 6 seconds for each meter you ascent. Monitoring the depth and time simultaneously can be a bit awkward and it helps if you just check the depth and count to 6 (mentally) for every meter you ascent. And in addition to this, check the timer a few times during the ascent as an extra check (say for every 5 meters 30 seconds should have passed). A nice thing about this method is you can read the total ascent time when you surface. Although I think at the end of the day one should be able to 'feel' if the ascent rate is right or not. And just use the bottom timer to make corrections. So this is what I do, any comments?

June 7th, 2007, 02:07 PM	#10 (permalink)
david_1(Offline) New Member Join Date: Jul 2006 Location: sussex Posts: 295	Quote: (Originally Posted by Gene_Hobbs) been reading on net today... This statement always scares me well if I came along and confessed to be an expert because I had read something,I must be right :-). we all read stuff on the net (your reading this) I have few good answers here to my question, but not what I wanted. I hoped some one would say go buy this comp put it in this mode it will then show you your accent rate in plain meter per min. why we accend at a set rate for diffrent parts of the ascent is whole diffrent question. :-) but thanks all even if a scared you on the way here :-) David