Safety Stop required ?

[Barry_Calgary]

Hi All newbie diver here thanks in advance for your responses. I recently took my open water certification required 4 dives in Ixtapa Mexico. All went without a hitch and the dive conditions were great, although I don't have anything to compare my experience to yet. Question is when I took my PADI classroom training it was communicated that we should always do a safety stop at 15 feet for 1 minute upon ascent. the dive master in Mexico didn't do this and neither did any of the other 4 divers in our group. Little confused, should I be doing a safety stop ? or did I misunderstand the requirements ?
Last 2 dives were at a depth of 60 feet.
Thanks for your assistance. Any feedback much appreciated.

 

[gurnie]

You should be doing a stop at 15 feet for 3 minutes. They are not mandatory, but a standard safety procedure in recreational diving.

 

[Quero]

Hi Barry,

Safety stops are not required stops--they are meant to give you a safety cushion against ascending too rapidly, but the way the dive tables are formulated, you are able to ascend directly to the surface at any time during your dive without a stop. However, many of us encourage our divers to do safety stops at the end of every dive. It's a good habit to get into. This stop is typically a three-minute pause at 15 feet (not one minute).

There have been times when my students and divers have asked why I didn't do a stop at the end of a dive but instead guided them straight to the surface. Every time I've had this questions, my divers simply didn't notice that we were diving at 15 feet for an extended period and had effectively done the "stop" despite the fact that we weren't "stopped" while we did it. It comes to the same thing, of course. Is it possible that your group was diving at a shallow depth during the safety-stop period and you simply didn't realize that you were performing your "stop" while swimming?

 

[SC_Hoaty]

I can see skipping the stop if the whole dive is shallow - 20 feet or less. I would have made the stop for the 60 foot dives. Some times the tail end of the dive is actually several minutes in 15 feet or so of water. Nice to spend the time seeing fish instead of just hanging out looking at your watch.

 

[SC_Hoaty]

And I see Quero posted as I was typing, and probably said it better than I did!

 

[Barry_Calgary]

Thanks Quero, you are more than likely correct we possibly were diving at or around 15 feet on our 3rd dive while surfacing. On 2nd dive to 60 feet we had to practice the Emergency ascent so that is why we didn't do a safety stop. Our first 2 dives were shallow dives around the 30 foot mark. Makes sense now.
Thanks I will definately get into the habit of performing a safety stop, I guess it made me think because I didn't see the other divers in our group performing a safety stop. I guess just because they are not doing it doesn't mean I shouldn't. Like you said good habit to get into.

 

[Quero]

Well, you know, "great minds" and all that.... :cool2:

 

[TSandM]

If you did a PADI certification class, you may remember Knowledge Review 1, Question 5. That's the table of how things compress and expand with depth, and by looking at it, you can see that the biggest proportional changes in pressure and volume are in shallow water. (For example, a volume of air at 33 feet doubles in size between there and the surface, but the same volume of air at 66 feet will only expand by 50% at 33feet.) The air in your lungs and the nitrogen bubbles in your bloodstream are both expanding very rapidly in the top 30 feet, and the safety stop was designed to make sure your ascent through that region was slow. If your entire dive has been shallow (say, 30 feet or less) you have absorbed so little nitrogen that bubbles aren't really a worry. Or, if you have been meandering slowly up through that part of the water, taking your time and looking at critters, there is no reason for a specific stop to be made at 15 feet.

As an example, here is a typical profile at one of our usual dive sites: We submerge and swim down a line to about 60 feet, turn right and wander gradually up to about 40 feet and inspect some pilings and a rubble field that used to be a wreck. From there, we turn back, and spend the whole second half of the dive working our way from 40 feet to the surface. We rarely do a formal stop, simply because the ascent rate (40 feet in 20 minutes or so) is so slow that it isn't necessary.

In addition, the safety stop can be omitted completely in an emergency -- and this is important to remember -- so long as the ascent rate doesn't exceed the rate of the model you are using for decompression. (And with the RDP, that's 60 feet per minute, which is really fast!)

 

[SC_Hoaty]

Well, you know, "great minds" and all that.... :cool2:

"great mind" on my end? More like this!

 

[Islandheart]

As has been saidalready, Safety Stops should be a routine, in certain situations they become required. Look at your RDP, study your D.Computer.

Now, Some students miss it during their 4 Open water dives, that their instructor briefs them, during the dives, they will be simulating a saftey stop and then they will make a 3 min safety stop.

Now most of these dives are in 35' or less of water, ALOT is going on and students miss it when the Instr gives a sign for "Stop- Level Off- 1 or 3Min".

If you could rewind your entire OW training and then play it back in slow motion, Many things would jump out and would click for you.

DCS applies to you, not someone else. Don't add to issues that could gives you DCS.

Listen during the dive briefing from the DM if they plan a safety stop. If they don't plan one, TELL THEM, you want to do one.

I teach my students that the RDP has three areas; Green Light, Yellow Light and Red Light. I ask them how they approach a traffic light ?

Now, plan your dive as you would compared to that traffic light.

Green: Safety Stops Routine and if you have an emergency situation you can blow through it.
Yellow: Safety Stops Required, hope like hell you don't have an emergency
Red: You just went into Deco ....................... all that applys !

Only one butt attached to your tank, guess who it belongs to !