Safety stop at 15'..........always

[Gombessa]

I don't really understand people who are personally offended by the notion of safety stops. I guess it can seem paternalistic and condescending ("Now be a good boy and eat your sprouts!").

I love safety stops. You can look around, work on trim, do a buoyancy check, do an air share drill, stare down your friends, etc.

For me, any additional time underwater is time well spent.

 

[all4scuba05]

Diver A and diver B have spent the same amount of time from their bottom depth through their safety stop depth, but diver B has been deeper than diver A at every point between the beginning of their ascent and diver B's arrival at the safety stop depth. As diver B was deeper throughout, he has had less opportunity to offgas.[/indent]Of course, it may not be that simple for actual diving. Slowing the ascent rates even more may give more time for offgassing, but it also gives more time at depth for ongassing and may require considerably more breathing gas (considering the longer times on top of deeper depths, both of which require more).

Of course, the last time I looked up actual research on ascents and DCS, the data seemed to strongly indicate that "normal" ascents *with stops* were vastly superior to slow (and very slow) continuous ascents given the profiles that were tested. I would not generalize that so far as to say it's never appropriate to ascend slow and steady, but it would not be correct to assume that it is safer to do so.

(

Interesting. Perhaps it is believed that the divers doing thir deco stops in the shallows are better off than the divers who do deep stops?

 

[SparticleBrane]

I don't really understand people who are personally offended by the notion of safety stops.

It's ego-driven and makes them feel inferior.

"Why would I need to do a safety stop? I can't get DCS!"

 

[ClayJar]

It could be a Type 2 symptom - common symptoms include headaches or visual disturbances, dizziness, tunnel vision, and changes in mental status

and also getting a head ache is from a C02 hit

My money would be on basic barotrauma.

A slow ascent and stops give borderline sinuses plenty of time to equalize slowly before there is enough pressure differential to cause pain. A faster ascent may result in pressure differentials great enough to cause slight barotrauma in poorly-equalizing sinuses (as evidenced by the headache).

I know if I think I'm a little stuffy, but not enough to call a dive, I can usually avoid a sinus headache by making extra-careful slower-than-normal ascents. (I've never had a terrible pain, blood-in-the-mask sinus incident, but a couple times a year, I may end a dive day due to a "sinus pressure" headache.)

 

[Gombessa]

Of course, the last time I looked up actual research on ascents and DCS, the data seemed to strongly indicate that "normal" ascents *with stops* were vastly superior to slow (and very slow) continuous ascents given the profiles that were tested. I would not generalize that so far as to say it's never appropriate to ascend slow and steady, but it would not be correct to assume that it is safer to do so.

I think the deep-stop method generally takes this into account. If the different tissues of your body on-gas and off-gas at different rates, slight pauses at some fraction of max ATA or 50% max depth, and minute-long pauses at 30, 20, and 10 fairly approximate a typical safety stop profile of a steady ascent to 15' with a 3min stop there, but the deep stop smooths out the curve without making it a linear ascent.

CERTAINLY, SLOW DOWN THE SURFACING!!!

Isn't that the truth. The "10ft-to-surface" is probably the most critical point, and yet 50% of the time I have little control over my speed, despite being "properly" weighted. Just means more practice is needed...

 

[scarefaceDM]

Come to think of it I would also agree...having suffered my share of the ol sinus head ache. And I do at times take a sinu tab to help the congestion.

It can be easy to mistake DSC symtoms with the common cold or signs there of.

My money would be on basic barotrauma.

A slow ascent and stops give borderline sinuses plenty of time to equalize slowly before there is enough pressure differential to cause pain. A faster ascent may result in pressure differentials great enough to cause slight barotrauma in poorly-equalizing sinuses (as evidenced by the headache).

I know if I think I'm a little stuffy, but not enough to call a dive, I can usually avoid a sinus headache by making extra-careful slower-than-normal ascents. (I've never had a terrible pain, blood-in-the-mask sinus incident, but a couple times a year, I may end a dive day due to a "sinus pressure" headache.)

 

[scarefaceDM]

Isn't that the truth. The "10ft-to-surface" is probably the most critical point, and yet 50% of the time I have little control over my speed, despite being "properly" weighted. Just means more practice is needed...

this tells me you are not properley weighted and you have not vented enough air from your BC. You should be able to maintain a 10 foot saftey stop...with a near empty tank( 500psi) and barley any air in the BC.

You are correct ...practice is needed. But I would also re check the weight and do a few various weight checks with a near empty tank and a full tank. But also work with an experienced diver that knows what they are talking about..

worked for me.

 

[SCUBA_Phil]

Safety stops vs. deco stops and old timers vs. current teachings. It all comes down to personal risk and what you feel comfortable with. In the old days we were diving on steel 72s and this limited your exposure. Today we dive with steel 100s, 120 & 130 doubles and rebreathers. The exposures can be significantly different! My current profiles for rec. dives is at 50% of the depth, I start to do 1 min rolling stops until 20 feet, here the stop is 3 min then another stop at 10 feet for 1 more min. Tech dives are done using VPM algorithm set to +3 or ratio deco with the last stop at 20 feet, then take an additional 6 min to get to the surface (one min at 18, 14, 11, 8, 5 up). I have used this to depths below 200 feet and exposures up to 150 min. It all comes down to risk! When I’m done with my dives, I feel good - so I use what works with me and is acceptable to my team mates!

Phil

 

[Gombessa]

this tells me you are not properley weighted and you have not vented enough air from your BC. You should be able to maintain a 10 foot saftey stop...with a near empty tank( 500psi) and barley any air in the BC.

You are correct ...practice is needed. But I would also re check the weight and do a few various weight checks with a near empty tank and a full tank. But also work with an experienced diver that knows what they are talking about..

I'm 95% sure it's a skill-based problem. With my current weighting, I've emptied the wing completely and can stay neutral at 10ft at ~300psi, and can slowly ascend to the surface with lung control. But when ascending normally during a dive, I think I'm just not able to get all the air out of the wing from the butt dump, and/or not venting enough out of the drysuit. Usually, it's enough for me to hold 10ft, but as soon as I get to 6ft, it's a one-way trip.

 

[2Tours N Iraq`]

I always do a safety stop at 15' then make a slow controlled ascent to the surface. I have my dive computer set to the most conservative rating and only on vary rare occasions does the alarm on my computer indicate that I am surfacing too quickly. The other practice I have is to carry a copy of the tables with me in my BC pocket so that in the event of a computer failure, I still can continue the dive if I have time remaining and then do a safety stop. I even had this happen once while diving in my local quarry.