View Full Version : Ascent Rate?
What does your training say you should do as an ascent rate and in practice how do you manage this?
Do you meet your ascent rates?
Does it matter if you do?
Whats an ascent rate?
Scotty Boy
22-04-08, 14:02
What does your training say you should do as an ascent rate and in practice how do you manage this?
Do you meet your ascent rates?
Does it matter if you do?
Whats an ascent rate?
SSAC manual states a maximum ascent rate of 10metres per minute, usually using a computer, or can be judged going by the rate at which the smallest bubbles from your reg ascend.
always meet my ascent rates
of course it matters, you run a much greater risk of getting a bend if you dont stick to a safe ascent rate :rolleyes:
its basic basic training!!
SSAC manual states a maximum ascent rate of 10metres per minute, usually using a computer, or can be judged going by the rate at which the smallest bubbles from your reg ascend.
always meet my ascent rates
of course it matters, you run a much greater risk of getting a bend if you dont stick to a safe ascent rate :rolleyes:
its basic basic training!!
Which computer and how do you know its set at 10mpm.
What are the issues with going faster / slower than your manual states....
suuntos are set at 10mpm i believe while alladin are set at 9mpm
me personally, i regularly use US navy tables, sometimes i have to come up at 20mpm but i do have other major safety factors built in to the dive plan if im doing this.
generally never faster than 10mpm, deco always slower still.
for any newbies reading this,
dont try and come up at 20mpm or you will probably get bent or worse!
Lizardland
22-04-08, 14:44
Ahhh... post-fundies afterglow? :D
I dive with a Sensus Pro data recorder which records depth every second. I once logged an ascent rate of over 200m/min :) I was in the shallows, no dive kit on and stood up quickly and that was enough to blow it off the scale...
Anyway, my computer (Shearwater) is set for 3m/min chunks, one bar lit means 3m/min, 2 bars is 6m/min, etc. On ascent I rarely see more than 2 bars lit. If I'm doing a no deco dive then I usually pause every few metres on the way up, first pause at about 3/4 of the depth, so the ascent rate never really gets a chance to get high.
If I'm doing deco then 9-10m/min to close to the 1st stop, usually pausing on the way to double check times/tables. Between stops is slow, I usually work up very slowly towards the end of the stop so that when the next one starts I'm pretty much at the right depth. From 6m up it's hand over hand on the line, not sure what it translates to but it's slow enough that the Shearwater won't even light one bar. I don't generally do a 3m stop as I start feeling seasick around that depth when it's rough.
Issues with going faster... well that's pretty obvious. I don't know what my computer does as it's there as a backup, I use paper tables so I'd modify that in the water. I don't worry about minor sudden depth changes though.
Issues with going slower... I've seen people run out of air from not planning for ascents properly. Some computers will hammer your deco if you don't do what it likes, I got rid of my Aladin Pro because of that. Go too slow and you might end up with a lot more deco than you planned for.
Cheers,
Stuart
Id like recreational divers to also have a think about this please.
I.e. no decompression diving.....
What does your training say you should do as an ascent rate and in practice how do you manage this?
Do you meet your ascent rates?
Does it matter if you do?
Whats an ascent rate?
Why?
Is this due to what you were told over this last weekend? Im guessing possibly incorrectly that you have an issue with the speed of ascent after training with SSAC and PADI?
Yogi Diver
22-04-08, 15:54
Interestingly,I believe PADI still teach 18 m/min? with a 3 minute safety stop at 5 metres, whilst most (all?) the other agencies are more or less standardised on the idea of a 10 m/min ascent with a 1 minute safety stop at 3 metres. (At least I know that's the SAA way.)
I have always aimed for less speed on the ascent. 10 is a MAXIMUM not a target. I use a Suunto computer which always calls for a 3 minute stop within a window of between 6 and 3 metres. If I've been deeper than 20 metres, I usually try to add at least a one minute stop half way up, especially if I've taken it into, or nearly into Deco, even though the computer doesn't call for it.
I still got bent though.:confused::o:(
There's still only one guaranteed safe way to avoid Decompression Illness. Don't compress in the first place!!:p
I thought PADI was a MAXIMUM ascent rate of 18m/min, which I recollected what I was taught. My daughter did her course less than 2 years ago and that was the same. However to not look any more of an idiot than normal I went away to check this!
However on some PADI sites online it mentions 60ft/min (around the 18m mark) but now or recently being reduced to either 30ft/min or 30ft/min for the final 30ft ie around 9m. I don't know if that's the new rules or latest recommendations. The ascent rate was always a MAXIMUM and not the target.
I also dive with a suunto and read the manual, realising it was giving a slower ascent rate and I aim to keep within that as the beeping is irritating. I would say I generally ascend quite a bit slower than the computer requirements in anycase and always aim to, and nearly always do, the safety stop. I haven't got in the habit of a deep stop yet. Although, going back to the drysuit venting thread, I generally ascent with my drysuit as empty as I can get it and therefore have to fin like mad to come up anyway, giving plenty of stops on my average ascent! :D
suuntos are set at 10mpm i believe while alladin are set at 9mpm
I thought that the "permissible" ascent rate of Aladin computers altered depending what depth you were at: i.e they allow to ascend faster when deeper & slower when shallower. :rolleyes:
As well as DCS, is there not an increased predisposition for pulmonary barotrauma after a speedy ascent rate (obviously if the lungs aren't voided quickly enough)? :eek:
I carry a small bag of ping-pong balls and release one every 2 metres on ascent. I have a monkey on the deck with a gong which he hangs over the side and bashes every time he sees a ball appear on the surface; the closer together the gongs, the faster I am ascending.
I have fewer balls the closer I get to the surface and therefore my ascent rate slows to give me the correct shape for my decompression.
Mind you, I had to change the monkey, the first one was epileptic, oh boy was I cold when I surfaced from that one but I'd run out of balls and had to come up!
I thought that the "permissible" ascent rate of Aladin computers altered depending what depth you were at: i.e they allow to ascend faster when deeper & slower when shallower. :rolleyes:
more accurate than i posted yes:o, i based the 9mpm on an average non deco dive as Aladins dont incorporate any safety stop unless you hit deco based on its algorithm.
i see the new ones can be manually adjusted to manipulate deco stops - ascent rates.
personal settings, FB settings or Russian roulette...:confused:
think i'd rather buy a monkey & a bag of ping-pong balls..:D
think i'd rather buy a monkey & a bag of ping-pong balls..:D
Hey, it took me five years of diving to realise it was 18 metres per minute not per second
Lizardland
22-04-08, 20:02
This might be an urban legend but the old tale is that 10m/min came about because that was as fast as two US Navy grunts could crank the pulley that lifted a hard hat diver off the bottom. 18m/min came about when they started using scuba and became free swimming. However that may be utter pish (sounds like it).
IIRC PADI tables are designed for 18m/min but less is recommended. Realistically, how many people can judge their ascent rate accurately without the aid of a computer/timer's display? I probably could if I had to but I can't remember the last time I had to.
Mind you, I had to change the monkey, the first one was epileptic, oh boy was I cold when I surfaced from that one but I'd run out of balls and had to come up!
I'd have given my monkey a good spanking afterwards if I'd had a problem with my balls.
Cheers,
Stuart
Yogi Diver
22-04-08, 20:10
I have fewer balls the closer I get to the surface and therefore my ascent rate slows to give me the correct shape for my decompression.
I have the same problem but Mrs Yogi wants me to stop diving? What's the problem?:D
This might be an urban legend but the old tale is that 10m/min came about because that was as fast as two US Navy grunts could crank the pulley that lifted a hard hat diver off the bottom.
i heard the same story from an ex-US Navy Seal (he taught me to dive) who used to be a test diver for the US Navy amongst other 'stealth operations':rolleyes:.
mind you, he also told me of his 265m dive on air from a submarine on a 'mark V'.
he even had a dive cert (which i seen) to approve him to that depth (on air).
i think he is 206 years old now..:D
Yogi Diver
22-04-08, 20:32
i think he is 206 years old now..:D
So you went to school together then?:D
So you went to school together then?:D
yes.. but it was dive school and he was the teacher, im only 72 as well you know. ;)
Lizardland
22-04-08, 21:02
i heard the same story from an ex-US Navy Seal (he taught me to dive) who used to be a test diver for the US Navy amongst other 'stealth operations':rolleyes:.
mind you, he also told me of his 265m dive on air from a submarine on a 'mark V'.
he even had a dive cert (which i seen) to approve him to that depth (on air).
i think he is 206 years old now..:D
I've often thought that the Seals and the SAS/SBS must be the biggest regiments with the easiest entry standards in the military given the number of 5'4", 18st ex-members that I've come across. Strangely, a lot of them seem to end up as BSAC or PADI instructors or on dive boats struggling with their snorkels... :D
I'd have given my monkey a good spanking afterwards if I'd had a problem with my balls.
Cheers,
Stuart
Unfortunately my hands were too cold by this stage. Fortunately my misses was there to administer the spanking instead.
I've often thought that the Seals and the SAS/SBS must be the biggest regiments with the easiest entry standards in the military given the number of 5'4", 18st ex-members that I've come across. Strangely, a lot of them seem to end up as BSAC or PADI instructors or on dive boats struggling with their snorkels... :D
the one i know is about 5'10" skinny as a racing snake, plastic kneecap, metal pinned and more shrapnel wounds/scars than jocky wilsons dartboard.
i think he fell over a lot while being drunk...:D
his name isnt 'steve austin' BTW ;):D:D
dive granny
22-04-08, 22:04
I use my computer, and watch the time and depth, make sure the arrow doesn't appear:eek: Did a couple of blue water ascents on the P.N. trip:D
Hickdive , you do make me laugh !
I shall buy you a pint should I ever meet you.
On topic . briefly ;
I ascend at on , or prefably below , the 10m/min indicated by my Mares M1 ( its in the manual ) using its handy bar-graph display and inaudible beeper.
I can even see it in the gloom of the Scottish Lochs cos it enven has a proper backlight.
I appreciate that you can probably ascend faster if you are deeper as its about the rate of change of pressure. ie a 1m change of depth at 30m produces a far less % change of pressure than a 1m change of depth at 5m.
But like all things safety related , better to K.I.S.S.
Cheers JB.
dive granny
22-04-08, 22:28
Johnny B, if you ever meet him you should have no bother recognising each other from your avatars:D Will he Hickdive;)
inaudible beeper
Oh, for an inaudible beeper - why's it keep beeping all the time anyway - bl**dy irritating. :mad:
Johnny B, if you ever meet him you should have no bother recognising each other from your avatars:D Will he Hickdive;)
HEY , WHATA YOU MEANA BYA THATA ???
Did I sound Mafia -ish then ??
DG , you wake up , find seahorses head in youra bed !!!!
;)
Oh, for an inaudible beeper - why's it keep beeping all the time anyway - bl**dy irritating. :mad:
Its trying to tell you something :D:D
Bit like the wife - best ignore it :)
Hickdive , you do make me laugh !
I shall buy you a pint should I ever meet you.
On topic . briefly ;
I ascend at on , or prefably below , the 10m/min indicated by my Mares M1 ( its in the manual ) using its handy bar-graph display and inaudible beeper.
I can even see it in the gloom of the Scottish Lochs cos it enven has a proper backlight.
I appreciate that you can probably ascend faster if you are deeper as its about the rate of change of pressure. ie a 1m change of depth at 30m produces a far less % change of pressure than a 1m change of depth at 5m.
But like all things safety related , better to K.I.S.S.
Cheers JB.
He's not that funny in person in fact i think he gets someone else to post for him bit like a ghost writer.:p
He's not that funny in person in fact i think he gets someone else to post for him bit like a ghost writer.:p
Good on ya , I'll buy the ghost a pint then :D
( Thats saved me £47.95 at Edinburgh prices - Woo Hoo ! )
dive granny
22-04-08, 23:55
HEY , WHATA YOU MEANA BYA THATA ???
Did I sound Mafia -ish then ??
DG , you wake up , find seahorses head in youra bed !!!!
;)
We were the only two on the P.N.trip who looked like our avatars.:D;)
Well, I don't have yellow skin...yet!
However, as we all know, the liver is evil and must be punished, so a few more drinks and I will be just like my avatar:D