Dive by computer?

I was reading another thread which sparked a question. I will go over the last dive to give you a idea what i am talking about it was max depth of 75' for 85 minutes. We dove a local lake we went over the dive plan before entering the water. We dropped down about 40' for a couple minutes to get settled then drop down to around 75' only stayed at 75' for about 5 minutes. Then went up to around 50' and the last 20 minutes went up to 15' to 20' back to our entry point.
So my question is we didn't really set a time limit on the dive by a table. We do however pay close attention to the computer and stay well with in our NDL then we always come up to 15' to 20' for a slow swim back which also should account for our stop.
I just wanted someones opinion on this I'm still new to diving.

perfectly acceptable practice for recreational diving, just be away that a computer failure will mean you thumb the dive, and it may end up being an end to the dive day unless you had everything logged to switch over to tables.

It is acceptable to ride the computer. I generally have a bit more planning behind my dives, but safety is the goal. At 75 feet you could have maintained that depth for around 35 minutes or so pushing NDLs.

I generally like to spend a bunch of time shallow (20 feet or less). Not mandatory, but not a bad way to end a dive playing in the shallows.

RonFrank:

It is acceptable to ride the computer. I generally have a bit more planning behind my dives, but safety is the goal. At 75 feet you could have maintained that depth for around 35 minutes or so pushing NDLs.

I generally like to spend a bunch of time shallow (20 feet or less). Not mandatory, but not a bad way to end a dive playing in the shallows.

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I guess the term I was looking for was "ride my computer" . I was diving 32% EAN so I could have defiantly stayed at that depth longer. But as you stated should I be planning more?

Some folks plan their dives down to the breath. Others barely plan at all.

I think how much planning is directly in relation to how complex the dive is. What makes a dive complex? Well mainly depth and overhead environments. If you run out of gas on a 20' dive not too much to worry about. If you run out of gas at 20' 500 yards back in a cave that's a big issue. So the type of dive you are doing can dictate how much planning is required.

I know my NDL for a max planned depth. I'm a good breather so that helps. Basically I don't plan much beyond that which is why I enjoy rec diving! I think tech diving would be a lot of work.

wausman:

I was reading another thread which sparked a question. I will go over the last dive to give you a idea what i am talking about it was max depth of 75' for 85 minutes. We dove a local lake we went over the dive plan before entering the water. We dropped down about 40' for a couple minutes to get settled then drop down to around 75' only stayed at 75' for about 5 minutes. Then went up to around 50' and the last 20 minutes went up to 15' to 20' back to our entry point.
So my question is we didn't really set a time limit on the dive by a table. We do however pay close attention to the computer and stay well with in our NDL then we always come up to 15' to 20' for a slow swim back which also should account for our stop.
I just wanted someones opinion on this I'm still new to diving.

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I haven't read the other responses yet so forgive me if I'm repeating.

First of all, the practice you're describing is generally referred to as "riding the computer". It's a perfectly acceptable practice in the sense that the power of the computer is in telling you if what you're doing is safe or not.

However, in the absence of planning your dive, riding the computer alone isn't enough to keep you safe. The computer can only only give you information about your status with respect to NDL's but it can't plan your dive for you.

One thing, for example, that you mentioned is that you didn't really have a time-limit for the dive. That kind of thing is a red-flag to me unless it was a conscious team decision to make the dive under those conditions. Other red-flags would be things like not having any kind of navigation plan or idea of what kind of a profile you intend to swim.

Keep that in mind as well.

R..

Riding a computer without even looking at it's planner or at your Tables is a bad habit. On single dive days it doesn't really matter, but it could easily bite you in the butt if you're doing repetitive dives or multi dive days. One long dive can equate to a very long SI or a very aggressive series of dive profiles.
Riding your computer also pushes you closer to your limits of NDL and air remaining. A slight lack of attention could easily push you over the limits.
Planning your dive keeps you from getting lax due to bad habits.

You should plan your dives to include Max depth, max dive time, and air/time usage (such as turn around psi/time).

For the first dive of the day I usually look at my Tables and plan my max depth and max dive time off of that. These are limits that I set not goals that I plan to reach on that particular dive. Meaning that I do not have to max out my depth and/or dive time according to my plan.
I also consult my computer to make sure I can do that dive without violating it. This is a good habit to get into especially if your doing multiple dive days, and especially if you have night dives followed by morning dives.
If you so choose you can plan your first dive solely on your computer's planner.

On my repetitive dives I look solely at my computer's planner. My computer will give me limits on my NDL at certain depths and I plan accordingly. As a personal rule, I always plan my dive time to be 5-10mins less than the maximum NDL my computer gives me at the max depth I set.

At the end of each of my dives[-]my dive day[/-] I usually calculate my letter group based off of my Tables, just as a habit. Sometimes I go off tables during the second dive, sometimes I stay on tables throughout the day.

wausman:

..... I just wanted someones opinion on this I'm still new to diving.

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Plan your dive - dive your plan .... as much as possible.

Based on your description, your dive might look like something like this:

What your your SAC? What tank were you using?

With my SAC and an AL80 I almost run out of air on this profile :depressed:

g1138:

At the end of my dive day I usually calculate my letter group based off of my Tables, just as a habit. Sometimes I go off tables during the second dive, sometimes I stay on tables throughout the day.

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How do u keep track of letter groups once you're off tables? Just assume your in the last group before your SI?

DiveNav:

Plan your dive - dive your plan .... as much as possible.

Based on your description, your dive might look like something like this:

View attachment 104101​

What your your SAC? What tank were you using?

With my SAC and an AL80 I almost run out of air :depressed:

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I was going to run it on your program, but you beat me there - darn job got in the way....