AOW class

[navyhmc]

The bonus of blue hole is that if you play your cards right, you can come away with an Altitude cert.

[Okc_diver]

when I did my AOW last year my instructor told me that diving at tenkiller or elmer thomas (for examples) was doing an altitude dive because we are not at sea level.

[mitsuguy]

Originally Posted by Okc_diver

when I did my AOW last year my instructor told me that diving at tenkiller or elmer thomas (for examples) was doing an altitude dive because we are not at sea level.

not sure of the altitudes there, but anything over 1000' amsl requires special procedures...

so, 500' amsl, not at sea level, but also, not an altitude dive... 1500' amsl, not at sea level, IS an altitude dive...

[Smashee]

Originally Posted by mitsuguy

so, 500' amsl, not at sea level, but also, not an altitude dive...

It can be, depending on the weather, your training and the tables you work from.

If the atmospheric pressure is less than about 990 millibar, then a dive 100m above sea level would fall into level 2 on the BSAC 88 tables and is classed as diving at altitude.

[mitsuguy]

Originally Posted by Smashee

It can be, depending on the weather, your training and the tables you work from.

If the atmospheric pressure is less than about 990 millibar, then a dive 100m above sea level would fall into level 2 on the BSAC 88 tables and is classed as diving at altitude.

I don't know about the BSAC tables, only PADI and US Navy...

Strictly from a recreational sense, according to the US Navy and PADI, 1000' is the limit, however, from a technical diving aspect, the US Navy goes a little more in depth - a dive deeper than 145' can be considered diving at altitude, when you are more than 300' amsl...

[navyhmc]

Originally Posted by Okc_diver

when I did my AOW last year my instructor told me that diving at tenkiller or elmer thomas (for examples) was doing an altitude dive because we are not at sea level.

Elmer Thomas at 1350' asml would be an altitude dive for rec limits whereas Tenkiller at 650' amsl would be condsidered a sea level dive. My understanding is that anything under 1000' is sea level.

The caveat that Samshee brings up with barometric pressure can influence things too. I have been diving during the summer where the water is at 870' and my computer is saying a morning dive is sea level. The last dive of the day had a thunderstorm rolling in south of us and the computer was advising it was a "Alt 2" dive-above 2000'. So the weather will definitely affect the altitude reading.

[Smashee]

Originally Posted by mitsuguy

I don't know about the BSAC tables, only PADI and US Navy...

Strictly from a recreational sense, according to the US Navy and PADI, 1000' is the limit, however, from a technical diving aspect, the US Navy goes a little more in depth - a dive deeper than 145' can be considered diving at altitude, when you are more than 300' amsl...

The BSAC tables cover diving up to 2500-3200m, depending on local air pressure. You're not really going to get much done at those heights, though. They treat altitude as air-pressure, so you can be classed as diving at altitude even at sea-level if the weather is particularly crap. Not unusual in the UK or here in Oz.

[mitsuguy]

Originally Posted by Smashee

The BSAC tables cover diving up to 2500-3200m, depending on local air pressure. You're not really going to get much done at those heights, though. They treat altitude as air-pressure, so you can be classed as diving at altitude even at sea-level if the weather is particularly crap. Not unusual in the UK or here in Oz.

I completely understand the reasoning behind the barometric pressure defining your table conversion factors to use, but at the same time, not many people carry around barometers with them while diving, which makes their version a little impractical for the majority of the diving public...

PADI's tables go up to 10,000 ft, or, roughly 3000m amsl, which, assuming clear skies, is .714 ata...

[Smashee]

[quote=mitsuguy;328982]

Originally Posted by Smashee

I completely understand the reasoning behind the barometric pressure defining your table conversion factors to use, but at the same time, not many people carry around barometers with them while diving, which makes their version a little impractical for the majority of the diving public...

You might want to have a look at them. It's a lot easier than the way I'm explaining it. I suck at explaining stuff like this. There's a few copies floating around on the net, if you don't mind a little copy-vio.
Impractical's not the way I'd describe them, compared to the eyestrain inducing layout of the PADI tables, but yeah, they probably are a bit much for the majority of the diving public. A lot of Brit divers swear by them. Or at them. Or something.

[mitsuguy]

Originally Posted by Smashee

You might want to have a look at them. It's a lot easier than the way I'm explaining it. I suck at explaining stuff like this. There's a few copies floating around on the net, if you don't mind a little copy-vio.
Impractical's not the way I'd describe them, compared to the eyestrain inducing layout of the PADI tables, but yeah, they probably are a bit much for the majority of the diving public. A lot of Brit divers swear by them. Or at them. Or something.

It would seem there is a lot of talk about those tables actually... some say they are conservative on the recreational side, and it sounds to me like they are almost dangerous on the decompression side when you compare their numbers to the software that is out there...