First dive at 40 meters - Newbies recreational

[KenGordon]

if you have a deco stop the it is a deco dive. You wrote your computer beeped to get you to do deco stops yes? You had to do a 2 min stop at 20m so that sir makes this a deco dive even if you say you only planned a dive not to exceed NDL limits. You say you had 1 min to NLD at 40m and struggled to ascend, while struggling you are finning and could have been in deco already but been back in NDL clock later as you ascended.

Some computers put in optional deep stops at about half depth steps. These are not mandatory stops but just for marketing purposes. To get a real, mandatory, stop at 20m takes some trying.

 

[Blackcrusader]

Some computers put in optional deep stops at about half depth steps. These are not mandatory stops but just for marketing purposes. To get a real, mandatory, stop at 20m takes some trying.

well he had another mandatory stop for 2 mins at 12 meters as well before final safety stop. No one has explained why his computer gave him that stop when he said he did not go into Deco. Maybe his computer gives 2 additional stops.

 

[KenGordon]

But swimming up is not "wrong" in rec diving, especially as beginner it might be easier.

Near the bottom it messes up the vis and damages the bottom, so it is a bad idea. In general it hides issues with buoyancy. On safety stops it is an extra hazard if they are using being vertical to allow finning to manage depth.

 

[KenGordon]

well he had another mandatory stop for 2 mins at 12 meters as well before final safety stop. No one has explained why his computer gave him that stop when he said he did not go into Deco. Maybe his computer gives 2 additional stops.

Nobody gets a mandatory 12m stop on a 5 minute dive to 40m on a single 12 no matter how slow they ascend.

 

[Blackcrusader]

Nobody gets a mandatory 12m stop on a 5 minute dive to 40m on a single 12 no matter how slow they ascend.

They took time to descend 20m and then once they go to 40m only had 1 min to NDL before starting an ascent they found difficult due to down current. Is it possible they exceeded NDL for a few minutes and not realized and the first part of the ascent?

 

[Tribal]

They took time to descend 20m and then once they go to 40m only had 1 min to NDL before starting an ascent they found difficult due to down current. Is it possible they exceeded NDL for a few minutes and not realized and the first part of the ascent?

It wouldn’t be a stop at 12, no matter what algorithm the computer uses. If you have 1 at 12 you will have 9 6 and 3 aswell and you will have like atleast 15 minutes of deco in total.

 

[Celt]

Congratulations ye did great, keep diving.

 

[KenGordon]

They took time to descend 20m and then once they go to 40m only had 1 min to NDL before starting an ascent they found difficult due to down current. Is it possible they exceeded NDL for a few minutes and not realized and the first part of the ascent?

Sure they might have had a 3m stop but not a 12m one. I used a zoop on my training course 60m trimix dive with accelerated deco. The deepest stop it game me was 9m and I did not bend it until 6m. Getting a 12m stop on a non GF computer (Ie one set to add deep stops aggressively) is actually impossible on a dive like this. My last 40m dive had 40 minutes below 33m and my deepest ceiling was 9m and then 20minutes of stops. A 12m mandatory stop would have been followed by hour(s) of backgas deco in the OPs case.

 

[David Novo]

That leaves the 2 min stop at 12 meters, I don't think that @David Novo understands this either.

You are right @scubadada. I do not understand why the computer was showing him to stop at 12m, hence the question.

 

[Blackcrusader]

Nobody gets a mandatory 12m stop on a 5 minute dive to 40m on a single 12 no matter how slow they ascend.

Some quotes... They are at 40m with 1min to NDL. My other point is that he sees 1m to NDL but that as the computer does not show seconds he could show 1m to NDL and only have 15 seconds left to exceeding NDL. He has to ascend and is he also watching his NDL at same time?

It must have been 30 seconds that we are flipping upwards and we only moved from 40 to 37

I fought the urge to inflate our BCDs (we are still breathing and we have air so there is no immediate emergency) and I made a very quick calculation (worst case scenario, we consume 5 times our SAC. 5x11 l/min round to 12, it is 60 l/min. with 150 bar that is 1800 liters, we have 30 min so no need to panic). So we continued to fin. Then, the computer again. Stop at 20 meters: 2 minutes

At this point, I would have been happy to be at 20 meters but I realized that I was at 28. Relief. We continued finning calmly and at about 25 meters, we saw the most magnificent reef we had ever seen. Wonderful colors but mainly yellow. Never seen such a beautiful scenery even at the Louvres. My wife released my hand grip and we swam towards the reef as there was no current there. I decided that we would do the stop there and inform the DM. The DM was slightly above us, still in control. I don't know how long we stayed there but probably more than 2 minutes.

Then the computer said: 12 meters - 2 minutes stop.