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

[Ed Hatfield]

Regardless of my computer if I skip a safety stop I seem to get headaches. Even when I ascend at the ft/sec 'rule of thumb' I also tend to get headaches. In the past I have ruined a perfectly good dive opportunity because I complied with the dive profile on the first dive and skipped the second because of a headache. It is even worse in cold water. Once I slowed down and doubled my ascent time and made my safety stop a mandatory stop - no more headaches.

 

[SparticleBrane]

Note that while many people "do the safety stop" (finning and holding onto something because they can't maintain buoyancy), directly afterwards they shoot to the surface from 15ft, sometimes doing this in only 5 seconds or less, leading to a ridiculous ascent rate where the pressure differential is at its greatest during the dive (eg, where a slow ascent matters the most).

While doing stops is important, I would also advocate slowing down on your ascent from the safety stop. It should take you at least 30 seconds to ascend from 15ft, doing the 30ft/min rule.

 

[all4scuba05]

Depending on the dive profile and who I'm diving with, I may do the classic safety stop or I might just do a really slow, but continuous ascent from 30 feet (usually taking five minutes or longer). They both accomplish pretty much the same thing ...

... Bob (Grateful Diver)

My thoughts exactly. I don't always do the safety stop. The other divers are sometimes passing me on the ascent line.

 

[all4scuba05]

Regardless of my computer if I skip a safety stop I seem to get headaches. Even when I ascend at the ft/sec 'rule of thumb' I also tend to get headaches. In the past I have ruined a perfectly good dive opportunity because I complied with the dive profile on the first dive and skipped the second because of a headache. It is even worse in cold water. Once I slowed down and doubled my ascent time and made my safety stop a mandatory stop - no more headaches.

Interesting...does anyone here think this is a DCS hit?

 

[Walter]

They are an excellent idea, but as he said - not required. I usually make extra stops and usually stay longer than 3 minutes. As olli mentioned, lots of us were diving for years before anyone did any safety stops. Of course, we also ascended twice as fast as recommended today. As time goes by, some of us learn and change the way we do things. Everything else being equal, diving is safer with safety stops. Slow ascents without stops are not as effective in preventing DCS.

 

[GrumpyOldGuy]

I view a safety stop as both an oppertunity to practice good bouynacy control and a wieght check. If I can stay horizontal without a line at 15' for 3 minutes with little or no air in the BC wearing 7mils, life is good. If not, its a good time to stop and figure out whats wrong.

 

[MXGratefulDiver]

Note that while many people "do the safety stop" (finning and holding onto something because they can't maintain buoyancy), directly afterwards they shoot to the surface from 15ft, sometimes doing this in only 5 seconds or less, leading to a ridiculous ascent rate where the pressure differential is at its greatest during the dive (eg, where a slow ascent matters the most).

While doing stops is important, I would also advocate slowing down on your ascent from the safety stop. It should take you at least 30 seconds to ascend from 15ft, doing the 30ft/min rule.

Yep ... it's way too common and a pet peeve of mine.

When teaching AOW, I stress this point ... and we do a timed ascent from safety stop ... they're often surprised by how "slow" they should be coming up ...

... Bob (Grateful Diver)

 

[TheWetRookie]

Interesting...does anyone here think this is a DCS hit?

I don't know about a DCS hit but I know for myself that the more time I spend in the shallows the better I feel when I get out. More time off gassing.

Most of my dives are on walls that lead into a bay/cove so it is easy to do a gradual accent while still enjoying the dive, (shore dives). The 3 minute safety stop is always done and then gradually make my way to the surface.

 

[ClayJar]

I always do "safety stops", and I'll gladly add "deep stops" if the diving permits (little point to one if you've only hit 36'). Although the NAUI dive tables don't *require* a safety stop, if you're using the NAUI RGBM tables, those actually do make it a requirement (they also make the 1-hour recommended surface interval a requirement, and you don't work them at all the same as "normal" tables).

As for extra-slow ascents vs. normally slow ascents with a safety stop, for recreational divers at least, it is mathematically trivial to see that the latter yields lower nitrogen loading for equal ascent times:

Diver A and diver B are at identical depths. At a given time, diver A begins his normal ascent to safety stop depth, where he waits for his safety stop time. Diver B begins his ascent at the same time, but ascends more slowly so that he is just reaching diver A as diver A is completing a safety stop.

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.​

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.

(But, to sum up, if you don't want to study all the physics and physiology and all that jazz, just make your controlled 30ft/min ascent, add the stops, and if you have air and time, certainly extend them. You may see something cool, or at least you can enjoy them, and they're good for you. AND CERTAINLY, SLOW DOWN THE SURFACING!!! )

 

[scarefaceDM]

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

Interesting...does anyone here think this is a DCS hit?