The Last 10 Feet

[RonFrank]

And what good does that do? What real useful info do you get from that?

Having a sample every 2 seconds does tell you how fast you ascend using a much more accurate sample rate.

It can also suggest if the dive profile is smooth, or if the buoyancy control is more of an issue. A sample every ten seconds is going to show a much smoother profile vs. a sample every 2 seconds.

Of course this is after the fact. But identifying a problem is the first step in fixing it!!! IMO, if one already has the cable to upload the info, sample away!! More information = more better.

Ron

 

[JeffG]

Having a sample every 2 seconds does tell you how fast you ascend using a much more accurate sample rate.

It can also suggest if the dive profile is smooth, or if the buoyancy control is more of an issue. A sample every ten seconds is going to show a much smoother profile vs. a sample every 2 seconds.

Of course this is after the fact. But identifying a problem is the first step in fixing it!!! IMO, if one already has the cable to upload the info, sample away!! More information = more better.

Ron

So you need your computer to tell you if you have an issue with buoyancy control and going from 10 sec to 2 sec sample times helps that???? I don't think so.

There is a difference between data and information. Going to a 2 sec sample rate gives you more data...but no more information.

 

[Rick Inman]

Even in the worst vis, I can usually see (vertically) the surface from 10'. I don't need a computer to tell me my ascent rate - I can see it. If the vis is so bad I can't see the surface, I can usually see the tiny bits of stuff in the water. I just try to keep the speed to, "real slow". I really could care less what the computer says later if I know I've done it right.
Due to some other comments, just for fun, on my last few dives I've made my final 10 feet ascent face up. You can really see your speed that way.
It's amazing the data you get when you stop staring at your computer.

 

[scubacucamonga]

When I ascend, I keep my eyes glued to the ascent rate indicator on my Cobra, and make sure I'm at only one or two bars. Wish it had a numerical ascent rate indicator instead of bar graphs.

Anyway, anyone know of a computer with a numerical ascent rate indicator AND a shorter sampling rate (2 seconds sounds nice...)? Would also be nice to have a little warning that comes up on the display and stays on which indicates you exceeded a pre-set ascent rate.

We use Cochran Commanders. They have the bar graph, but also show 'WARNING!' and emit a sound if you ascend faster than a preset threshold. You can set the threshold and the granularity (sampling rate) of the profile. You can also upload to PC (with an optional cable and software)

I like them because they can automatically tell the difference between salt and fresh water (or two wet fingers on the probes), and they are easily changed from Air to Nitrox and back. They hold data for 500 dives, and the backlight is a very cool red-orange...

 

[BuoyantC]

I like what Rick Inman says about not staring at your computer. There may be a time when you may not have that "crutch" available. For example, you could be using a rental analog depth gauge when your computer fails on a dive trip somewhere.

Try doing some shallow ascents looking up and not at your computer until you get the "feel" for it. You can look at your download later to check your ascent time and grade yourself.
--------------------------
Dennis

 

[devilfish]

Just for the heck of it, when on a boat drop the computer on a rope to 10 feet and rip it out fast. See what information the computer shows from that depth. I bet not much.

 

[DandyDon]

Just for the heck of it, when on a boat drop the computer on a rope to 10 feet and rip it out fast. See what information the computer shows from that depth. I bet not much.

:lol: On the last day, after the last dive, as you may lock out your computer for a day or two.

 

[pt40fathoms]

Most dive computers "store" the dive at 10 second interval sample rates, although some can be set to a higher sample rate. Remember, this is "storage" sample rate, not display refresh rate. The refresh rate of your dive computers display should be fast enough to control your ascent with little noticable lag time. If your dive computer refreshed its display only once every 10 or even 2 seconds, it would be nearly useless.

 

[Charlie99]

:lol: On the last day, after the last dive, as you may lock out your computer for a day or two.

Not really, Don. IIRC, you have an Oceanic. Other than showing a fast ascent reading a super fast ascent has no effect on the simple model used in the Oceanic/Pelagic computers. It is up to you to compensate for "bad behavior" on previous dives.

With the Suunto RGBM emulation of RGBM the fast ascent may reduce the NDLs for future dives for up to the next 100 hours, but it won't lock you out.

 

[jaycanwk]

I havn't bought the extra sofware for downloading my dive profiles yet but I suspect it will show fast accents stored all the time because when I reach for my comp that is attached at my side and swing it around to read it, the accent indicators always flash in the red zone from the speed of bringing it upto my face from my side. Does this information actually get stored that way?