Sudden surfacing after 30 min @ 90 feet --A dilemma...

[Bubbletrubble]

If you did not have a deco obligation and you did not exceed the recommended ascent rate on your computer (33 ft/min), then missing the optional safety stop is not a big deal. It means that you still had a very low risk of DCS. In your case, the risk of bubble-pumping (caused by re-descending to make up the missed safety stop) probably outweighs the risk of DCS.

For the two divers on air who may have blown a minor deco obligation (let's say 5 min at 10 ffw) and were asymptomatic for DCS, it would probably be best for them to stay on the surface and take it easy. With medical facilities and a hyperbaric chamber nearby, that's what I'd be inclined to do. Some divers might recommend going back down to make up the deco stop. That would probably be OK so long as the shallow deco stop is extended (10-15 minutes) and gas supplies allow for that.

If either of them began to show signs of DCS, then they should get on oxygen ASAP and head straight to the nearest hyperbaric chamber.

In case you're interested, here's a chart illustrating U.S. Navy management for Asymptomatic Omitted Decompression (taken from the U.S. Navy Diving Manual):

On a side note, it sounds to me like the divers on air never had their computers trip over into deco mode. The last thing you want to do in that situation is lose buoyancy control. It's very strange that experienced divers would ever have a problem like that. That's two glaring errors on one dive.

 

[DC53]

45 degrees is a slope not straight down. Are you saying you went straight down along the slope to around 70-90 feet?

As to what you did, two buddy teams one team panics about their deco obligation and thinks they need to ascend and takes your buddy with them. Like others have said you did fine ascend normally, do not put yourself in danger, skip the optional safety stop. Figure out the problem on the surface.

Next have a little chat with these "experienced" divers about their dive practices while they buy you and your buddy beers for cutting your dive short.

Ok, I meant 45 degree down slope, "straight down" as in keeping moving, giving a pretty short descent time.

I think everybody knew it was a screw up, nobody was really wanting to discuss it in depth. In posting it I was just trying to learn from the experience so as to respond best if/when I ever encounter something like that again, as I imagine I will at some point.

 

[DC53]

If you did not have a deco obligation and you did not exceed the recommended ascent rate on your computer (33 ft/min), then missing the optional safety stop is not a big deal. It means that you still had a very low risk of DCS. In your case, the risk of bubble-pumping (caused by re-descending to make up the missed safety stop) probably outweighs the risk of DCS.

For the two divers on air who may have blown a minor deco obligation (let's say 5 min at 10 ffw) and were asymptomatic for DCS, it would probably be best for them to stay on the surface and take it easy. With medical facilities and a hyperbaric chamber nearby, that's what I'd be inclined to do. Some divers might recommend going back down to make up the deco stop. That would probably be OK so long as the shallow deco stop is extended (10-15 minutes) and gas supplies allow for that.

If either of them began to show signs of DCS, then they should get on oxygen ASAP and head straight to the nearest hyperbaric chamber.

In case you're interested, here's a chart illustrating U.S. Navy management for Asymptomatic Omitted Decompression (taken from the U.S. Navy Diving Manual):

On a side note, it sounds to me like the divers on air never had their computers trip over into deco mode. The last thing you want to do in that situation is lose buoyancy control. It's very strange that experienced divers would ever have a problem like that. That's two glaring errors on one dive.

Yes there were some errors. BTW can you explain "Eligible for Sur-D"?

 

[Bubbletrubble]

*post deleted due to incorrect information*

 

[fppf]

I believe that "Sur-D" is the proprietary name for a surface gas delivery system specifically designed for divers doing in-water recompression. It provides compressed gas (high oxygen mix) from the surface which is fed through a long low pressure hose to the diver who is hanging out at a depth of 10-20 fsw. Perhaps some Navy guys will chime in about this...

"Sur-D" stands for Surface Decompression.
The definition of Surface Decompression is decompression at the surface using a recompression chamber.

 

[Bubbletrubble]

"Sur-D" stands for Surface Decompression.
The definition of Surface Decompression is decompression at the surface using a recompression chamber.

Thanks, fppf. You're right. Boy, was I off! I just skimmed the part of the US Navy Diving Manual where it describes what Sur-D is.

 

[openmindOW]

Thank you for posting, DC53.

What quarry? Where is it located? What kind of computer did you have?

 

[Diver Tim]

In case you're interested, here's a chart illustrating U.S. Navy management for Asymptomatic Omitted Decompression (taken from the U.S. Navy Diving Manual):

Looks like you may have an old version of the Navy Diving Manual... I looked at Revision 6, and the chart looks a little different. It's available for download here SEA 00C3 Diving Publications and Technical Documentation, along with applicable advance change notices, if you're interested.

 

[Bubbletrubble]

Looks like you may have an old version of the Navy Diving Manual... I looked at Revision 6, and the chart looks a little different. It's available for download here SEA 00C3 Diving Publications and Technical Documentation, along with applicable advance change notices, if you're interested.

@Diver Tim: Thanks for pointing that out. Here's the new version of the table excerpted from the 2008 USN Diving Manual (Rev. 6):

Hope people find it useful...