Recreational Ascent Rate in the last 15 feet

[rsingler]

slowly make my way to the ladder and hang out at about 5 feet letting others go up

^---- this

 

[MrBigfins]

From 20 ft to 5 ft I go much slower than most divers I dive around. Once I hit 4 or 5 ft I tend to pop up faster than I probably should. In warm water I tend to do 5 min stops at 20 ft and slowly work my way up. I'm rather large and consume copious amount of whatever gas I'm breathing, so I tend to be surfacing before others and I take my time without feeling rushed

 

[Johnoly]

.... Well, actually it started when I looked at my Perdix tissue map while hanging out at the stop, and then went, "WTH?!"........

With many brand new divers that 'geek-out' on the newest technology and buy the "Tissue" computers, I think it's really GREAT that they can see the tissue graphs. They may not understand m-values and compartments etc, but when they see that graph CLIMB, they really understand that's bad and it changes their ascent rates. As more dive computers start to incorporate easy to see graphs and Instructors teach what the graph means,,,we'll hopefully have less accidents and more safety minded divers. I have friend that I dive with to 3 digit depths, multiple tanks a day, and they skip any 3 min safety stop as long as the deco light is not lit up.

 

[Saboteur]

I do mostly boat diving, and to "bake in" the slow ascent from safety stop so I don't have to pay too much attention I do my safety stop at 15' about 20 yards off the end or to the side of the boat, then slowly make my way to the ladder and hang out at about 5 feet letting others go up or just waiting a few minutes, then surfacing. It probably averages to less than 15 fpm. Plus it gives me a chance to breath down my tank safely while still looking around at the marine life.

I try to do pretty much the same thing. I let everyone get on ahead of me then try and wait a minute between 5-10 feet then try to drift slowly up from 5 feet. I’m sure the DM’s and other divers are cursing...FFS what is he doing we need to get going!?

 

[Jay]

If you ask me now, the correct answer for any rec dive after #1 is 10 fpm or less. The range line is now hot, ladies and gentlemen. Fire away...

(BTW, for the lurkers reading along with this thread, what is being advocated applies only to 0-15, or 0-30 feet. Ascending this slowly when deeper in the water will add to your gas loading in "slower" tissues, and is not helpful.)

This is a super nice poll ... I just love it

I'm wondering ... and I don't want to derail an nice clean poll, if you want to add into the poll:
•given what we know re SurfGF/GF99, a yes/no answer to if dive computer ascent warnings should be variable or not?
•and if divers have shifted from a 3min SS to a 5min one after studying their SurfGF/GF99 data?

re Ascent rates ... my feeling is that we know enough now for them to be so, and from deep Rec depths (close to 40m) perhaps the US Navy Frogmen's* rate of 60ft/min(18m/min) is an ok maximum until ~20m depths. I tend to do the super-slow ascent from ~10m which is where it seems all the GF fun starts. (* history: Alert Diver | Ascent Rates)

re longer SS. IMO you get good 'bang for your buck' with these and I do 5min on 90% of dives (exception being if it's a shallow <20m dive with a low SurfGF).

 

[rsingler]

Hey, thanks!
I think the SurfGF question is sufficiently Shearwater-specific that I'll pass on that addition for now. But that might deserve even its own thread!
Variable ascent rates ARE incorporated into a few computer brands depending upon depth. I'm not sure any mfr will consider allowing you to put in your own version of a "safe" ascent rate, for liability reasons.
I'll see if I can edit the poll to ask about 5 min stops. Good suggestion - I use them lots as well.
EDIT: Poll changed. You can enter two responses now - one to each question. Ignore the percentages assigned to each answer - they're now meaningless with two questions.

 

[Altamira]

I spend more time on ascent in the last 15 ft primarily because I use the extra time listening and looking around very carefully for overhead boat traffic or other obstacles. The extra off-gassing is an additional benefit.

 

[happy-diver]

Takes five or ten minutes post stop, peeping at weird drifting creatures
and then lining up the boat and waiting for all the floating people pulling
along the line and the fin hander offers until I surface climbing the ladder


mask on face reg in place fins on feet till bum in seat

 

[stepfen]

@rsingler congratulations for yet another great post.

I had seen these heat-maps in Subsurface but until this thread I though there were something about body heat, hence irrelevant to me as I do warm water dives only :S Oh my...
Finally I know what all these are about. Thanks Rob!!

So here is how I've been handling my ascents although I didn't know about heat-maps till now:
- Local shore dives (solo or with friends): I do the dives so that I reach SS depth with at least 700psi/50bar of air left in my 15lt tank (plus my 7lt pony when solo which is for emergencies only hence stays out of all these calculations). Then I slowly wonder around at 15ft/5m until I reach the entry point and/or 400psi/30bars or so. That usually means I stay at 15ft at least 5, usually 10 minutes or more - usually I don't even bother to check the SS timer. After this I try to ascent slowly but few factors make this difficult. They include: I like/want to ascent with vertical body position for the last feet/meters so that I can easily check the situation on the surface around me. Since I am almost 6.5ft/2m tall - if my dive computer is at 4-5ft my head will be practically out . Another factor is that my suit's buoyancy increases a lot towards the end and since I am vertical (head up) I find it difficult to kick downwards to compensate. I am not rocketing - but usually my final ascents are not that slow - I think my longish SS compensate for this.

- Guided group dives (usually by boat). Here I usually follow the group, which means slow/gradual ascents (I think I've never done a "square" profile dive) to SS depth and then wait for everybody's computers to count down 3 minutes SS. Then for most people the usual "rocket" to the surface takes place. In these cases I try to stay behind as much as possible, but usually even for me it is just about a minute or less. Few times I tried to stay down while people were removing gear and getting up the boat etc and dive guides/instructors had to put their masks back on to check if everything was ok with me. In all cases I got the impression they got slightly irritated by me not following the rest of the group.

 

[dmaziuk]

slowly make my way to the ladder and hang out at about 5 feet letting others go up

^---- this

... is easy in calm water with no current. In the dark and with a bit of a chop, not so much.