diving ascent times/safety stops.

[snailinpails]

Ok. so i got my open water certification but im still unsure of a few things. my biggest worrie is my assent and at what depth does my regular 80 cubic inch tank become toxic?
i know im only suposed to go 60 feet maximum but im asking these as scenarios.

ok so say im 100ft under water. is it true that id do my first saftey stop at 50 feet?or would i want to break it down into 4ths and stop at 75 50 25.

sorta the same for an 80ft depth im asking would i stop at 40, 30, 15?

and for my basic 60ft dive i was taught to stop at 30 and 15 feet. for 3 to 5 minutes each.

and also should i be logging all of my dives? If so what kind of log book should i get?

 

[lowviz]

Jason,

Some "rules of thumb."

Don't dive deeper than your tank. So for an 80 cuft, you should limit yourself to 80'.

Don't sweat the deep stops for now, just pay close attention to gas management. Much written on this. Search on Lamont and rock bottom.

Safety stop: 3 minutes at 15' is good, more is better. Practice asending slowly with one hand held up for the last ten feet.

If your RMV is greater than 0.5, you won't hit deco on an 80.

Go for it...

 

[snailinpails]

ok. thanks for the quick response...
is rmv air consumption?
also are you saying that on an 80 foot dive only stop at 15 feet? or is that for a 60 foot dive? and how fast should i do the 1 handed assent to the top?

 

[xs86]

hey i am Snailinpails dive buddy. how do you measure RMV?

also does RMV matter for a 60ft dive?

 

[lowviz]

...//...is rmv air consumption? ...//...

Yes, it is your rate of air consumption. Look into this.

...//...also are you saying that on an 80 foot dive only stop at 15 feet? ...//...

Yes. Throw in one minute at 40' if you want to practice for the future.

...//...and how fast should i do the 1 handed assent to the top?

Under control, 30 feet per minute, which is a fairly useless number. Try to keep your final ascent at one foot every two seconds, this is something that you can estimate.

(One hand above you can save you from an unfortunate meeting with an overhead object...)

 

[TracysaCADiver]

Now I am not an instructor, but my PADI book mentions going no faster than 18m/60 ft per minute. Also, if you are diving with a computer, your computer also should indicate if you should slow down or not.

 

[kundalinichi]

As your a newly certified diver, your diving air.. technically the contents of the 80 cu. ft. tank wont become 'toxic' untill you hit a PO2 of 1.6 which is at 218ft so you dont have to worry about that for quite a while. Stops every 10-15 feet is not a necessity with no-stop diving and can only complicate things.

If you buy a dive computer, depending on what kind, it may give you an option to do 'deep stops' where on a 100ft dive, it will give you a 1-2 minute stop at 60ft or so, but YOU should still plan your ascent so you have enough gas to complete a safety stop, with a reserve. You wont be making multiple stops like you are talking about untill you get into decompression diving. Just follow a 30fpm max ascent rate. So from 60feet it should take almost 2 minutes to get to your 15ft safety stop.

Alot of these questions should of been answered in your OW class.. and you surely should of logged your certification dives.

 

[snailinpails]

im a college student i cant afford a dive computer

 

[lowviz]

Here is where the "personal buy-in" comes into play. It is all in the link below. If your safety means more to you than the convenience of a quick answer, you were well served.


http://www.scriptkiddie.org/blog/2010/09/19/rock-bottom-and-gas-management-for-recreational-divers/

 

[lowviz]

im a college student i cant afford a dive computer

Don't need one, but you may find that they are a great convenience.