Premature Surfacing....

[Ron G.]

How should these two situations have been handled:

- Starting at about 60', diver slowly (and unexpectedly) rises to the surface. On the surface for only 5-10 seconds, gets control and returns to 60' for the uneventful balance of the dive.


- Starting at about 45', diver over-shoots a 15' safety stop and ends up on the surface. On the surface for 5-10 seconds, gets control and returns to the 15', three minute safety stop.

Thx.

Ron

 

[Web Monkey]

- Starting at about 60', diver slowly (and unexpectedly) rises to the surface. On the surface for only 5-10 seconds, gets control and returns to 60' for the uneventful balance of the dive.

Depends on the dive time and profile. A safety stop is recommended, but not mandatory, so a missed safety stop shouldn't be a huge problem. Multiple dives with a very short surface interval are treated as a single dive, so it would depend on how long the first dive was, and how long the second dive was.

However all things being equal, once you're on the surface, it's safer to consider the dive over. Depending on how much nitrogen you've absorbed and how it's off-gassing, multiple ascents and descents increase the risk of DCS.

- Starting at about 45', diver over-shoots a 15' safety stop and ends up on the surface. On the surface for 5-10 seconds, gets control and returns to the 15', three minute safety stop.

Same as above. It depends on the dive profile and time.

However, the bigger question is "Why does the diver keep losing control?" For a SCUBA diver "Whoops, I'm on the surface! How did that happen?" is the equivalent of a teenage girl saying "Whoops, I'm pregnant! How did that happen?"

A diver that can't control his/her position in the water column needs more training and practice before Something Bad happens.

Terry

 

[Teamcasa]

To me it has more to do with the rate of assent, how long and deep were they and why the loss of control.
Without those details, it is hard to say. However, if the assent rate was too fast, the dive is over for the day or two.

 

[dpbishop]

The first is not a problem in itself, although the cause of the assent should be determined and corrected. While 'bounce' diving is frowned upon, if you are within No Decompression limits and the assent is 30 ft/min or less, the risk of complications are minimal.

The second incident is problematic. A rapid assent can cause an embolism, which can cause unconsciousness. Better to be on the surface where aid can be rendered then underwater where it can lead to drowning. I know of at least one incident locally where that was the case. Of course it depends on the dive profile. I will occasionally end up at the top when wrestling with a lobster, but only from depths of 10-12 feet, and the assent is generally pretty slow.

 

[String]

If the ascent rates are in limits and no mandatory stops i dont see a problem with either scenario.

 

[InTheDrink]

Just to add my two cents - my first (misguided or at least ill-fated) attempt at inflating an safety sausage (no reel and grabbed line too early) took me from 5.5m to 1m in, well, maybe 2 seconds. Maybe 3, maybe 1. In any event, rather quicker than I'd planned and certainly outside rate limits. I immediately went back down again tom complete the safetgy stop (and had no ill effects).

Out of curiosity, was this the correct action? I hadn't quite hit the surface so I figured I'd just come back down again. I feel it was the right thing to do but happy to be corrected. FYI the dive was abour an hour and to about 25m. And yes, I felt very embarrassed at the time, but after some beers later that night found I wasn't the first one to shoot up holding a sausage.

Thanks, J

P.S. I've practised SNB deployment rather more successfully since then

 

[nereas]

First I would recommend nitrox for all diving.

Second, I would say never to return to depth to complete a safety stop. Instead, say on the surface, return to the boat or shore, take a longer surface interval, or forego any further diving today.

 

[underwasser bolt]

well said. this diver needs more practice and/or training.

 

[diver 85]

How should these two situations have been handled:

- Starting at about 60', diver slowly (and unexpectedly) rises to the surface. On the surface for only 5-10 seconds, gets control and returns to 60' for the uneventful balance of the dive.


- Starting at about 45', diver over-shoots a 15' safety stop and ends up on the surface. On the surface for 5-10 seconds, gets control and returns to the 15', three minute safety stop.

Thx.

Ron

Did these 2 events happen to the same diver???---what ever the answer is(& I'm assuming it was the same diver), said diver needs some more instruction---on proper bouyancy---& control...Sounds like the diver(s) might have been underweighted OR had a bunch of air(too much) in the BC....Either situation needs to be resolved.....

 

[nereas]

well said. this diver needs more practice and/or training.

Sometimes a current or deep swell can push you up. I actually had this happen once, next to a harbour jettee while with a student who lost control of her buoyancy. I went up with her.

Missing a safety stop warrants some additional procedures, at least a longer surface interval, say 2 hours, if not ending all diving that day.

Just to be safe.