Ascending and then descending straight away

[Jamesbeckett]

Hey guys new to scuba.
Yesterday i went for my 2nd dive.
We did 2 30min dives 1st dive we went 20m deep for 30mins. But on the 2nd dive we were 15m and about 15min into my dive i lost my buddy so i slowly ascended then saw i was abit too far from boat and decided to go back down to swim back towards boat and hopefully bump into my buddie i thought as i was in reasonably shallow water that this would be fine but now that i think of it i probably shouldn't of went back down! I feel fine being the next day but is this practice dangerous and should i refrain from doing this again. Cheers

 

[Ben_3]

If I understand correctly you were very well within NDL, so you were ok to go up slowly and or back down. Do try and make your safety stop on all ascents. Welcome to this great hobby!

 

[Fastmarc]

I agree with the above, however you are now diving solo since you now have no buddy. Unless you have been trained for this and have the required gear, this greatly increases the risks. I think in this situation it would have been better to stay on the surface while you make your way over to the boat. The crew on the boat would also have been able to keep an eye on you during this.

 

[wnissen]

If I understand the point of my Open Water materials, the goal is to get you to the surface and establish buoyancy, as typically it's easier to deal with any issue (lost buddy, equipment problem, navigation problem, etc.) at the surface with its infinite supply of air and superior viz. So your default response would be to stay on the surface and swim back to your buddy or the boat. That said, there are plenty of scenarios in which I might descend like you did, such as unexpectedly large waves or current at the surface, or boat traffic. Obviously one doesn't enter the water expecting problems, but it is helpful to think in advance about what you'd do. Good on you for thinking about your actions!

 

[arew+4]

I've been on quite a few shallow dives on structureless rubble reefs with limited vis. On many of them it becomes necessary to pop up and take a heading to the boat at the turn pressure. You just go up as slow as you can. Give the boat a big ok, set the line on your compass and finish the dive

 

[Cap335]

The unanswered question is where was the buddy, did they ever get back together. If you are going back down you should find bubbles and follow them down looking for your buddy.

 

[Steve_C]

If you do not see his bubbles rising, then signal to the boat so they know where you are. Make sure it is an OK signal. Personally I dislike swimming on scuba gear on the surface. If I do not see buddy I would drop down about 5 or 6 ft, assuming I had lots of air, and then swim toward boat. If it is a long haul, I might pop up once or twice to signal boat and verify my heading. Currents can throw you off.

I is much easier to see the bubbles from up on a boat then it is on the surface and DMs on boats are very good at it.

 

[Esprise Me]

If you're diving with a computer, it should be able to handle this scenario for purposes of calculating NDL. But I find it interesting to play around with tables when thinking about these scenarios. If you didn't get a set with your OW course, you can still buy them and teach yourself how to use them. It's interesting to compare two short dives with no surface interval to one longer dive. No table or algorithm is a guarantee, of course, but it's neat just to get a sense of how things change (or don't) when you vary your dive plan.

 

[Bowers]

Hey guys new to scuba.
Yesterday i went for my 2nd dive.
We did 2 30min dives 1st dive we went 20m deep for 30mins. But on the 2nd dive we were 15m and about 15min into my dive i lost my buddy so i slowly ascended then saw i was abit too far from boat and decided to go back down to swim back towards boat and hopefully bump into my buddie i thought as i was in reasonably shallow water that this would be fine but now that i think of it i probably shouldn't of went back down! I feel fine being the next day but is this practice dangerous and should i refrain from doing this again. Cheers

The buddy stuff aside, to answer your question about physics... coming up should be no faster than 30ft/min, but going immediately back down is no threat to your safety from a physics standpoint. You must ascend slowly to allow time to off gas without bubbles getting stuck in your tissues, but you can descend as fast as you can clear your ears and your body will have no trouble keeping up with the compressing nitrogen. With that said... make sure your checking your computer so that you dont pass ndl time, or with tables remember that anything less than 10 minutes at the surface is still just 1 dive so you must not pass your ndl that you previously planned.

 

[Jamesbeckett]

Cheers for the response guys. Yes the current was a bit strong and i preferred to swim down toward the boat. I also did manage to bump into my buddy on the way back. Il take in all of your advice and its much appreciated. Thanks