Don't use a dive computer?!

[Brandon]

Consider this (quite realistic) dive planning scenario:

The dive site is a pinnacle with a 100' bottom, rising to within 15' of the surface. The boat is tied to a mooring ball which is anchored to the top of the pinnacle. The operator tells you that time on this site isn't restricted, but they want you back on the boat with 500 PSI. It's your third dive of the day, you're feeling great and energized by the fantastic diving you've had so far, and you want a nice long dive of at least 90 minutes. During the briefing, you're also told that there's an octopus hole down at 60', and you and your buddy decide that you really want to check it out.
​

How do you plan a dive that allows you to safely meet all of these goals? How does your computer fit into that plan?

On the deck of a dive boat, the "plan" you'll most frequently heard discussed by computer divers for this dive goes something like this: "We'll descend to 60' (or maybe deeper), stay there until we start to run out of bottom time or air, then move to a shallower depth until we're low on air or run out of bottom time."

That's not much of a plan, but it's done every day...

-B

 

[Thalassamania]

...`but it's done every day and dive incident statistics continue to drop.

Reference please.

 

[Brandon]

Heheh... you caught me before I edited it. I was trying to be charitable and not start a debate, but I couldn't talk myself into believing that statement.

-B

 

[Tropicalwolf]

IMO, I can't believe how many rookies totally rely on computers. There is a huge difference between "learning to dive" and "learning how to use a computer." Those who know what I mean will understand...

 

[Rhone Man]

I NEVER use a computer. I use TWO !

Yeah, but you know the other old saying: a man with a dive computer knows his NDL, but a man with two is never sure... (paraphrased from "a man with a watch knows what time it is, but a man with two is never sure").

 

[phillybob]

I also do my tables and use planning software the night before. Now I'm coming up with all kinds of 'answers'.

 

[tech_diver]

Being told that the Costa Rican diving public thinks I’m stupid and lazy because I use a dive computer made me think I was falling for a troll. Of course, I have used at least a half dozen different tables over my diving career and when planning a deco dive I still run the profile past the Canadian tables (DCIEM) so I guess I’m only half stupid.

I value the experience and wisdom of my diving elders. They have a great deal to teach us and their first hand knowledge of diving history is a treasure. We owe so much to those who went before.

HOWEVER….

Almost every advance in sport diving that made things easier and safer has been met with resistance from some elements of the diving community. Typically, this resistance is from the wise, old divers because new divers simply dive the way they are taught.

So let’s take a stroll down memory lane through those golden days of yore with a few quotes from elders of diving. These are things I was actually told by wise experienced divers over the years. The year of the quote is approximate but these are things I was actually told…


Early 1990s…
Dive computer? No way am I going to trust my safety to an electronic instrument immersed in salt water. I have my watch and my depth gauge. Dive computers will kill people.

Mid 1980s…
Bouyancy jackets are crap. It’s just more junk they’re trying to sell to us. A properly trained diver with good skills can handle controlling his buoyancy.

Early 1980s…
Alternate second stages are just another example of the manufacturers working with the training agencies to sell us more gear we don’t need. Buddy breathing has worked for the Navy for decades and they know what they are doing.

Late 1970s…
Do not put one of those stupid air gauges (SPG) on your breathing system! If the face of that gauge blows out you will lose your entire air supply. You stick to a J-valve. It’s tried and true.

I didn’t even go into all stuff surrounding the advent of nitrox.


How did we ever survive....

 

[koozemani]

There might not be a trip if auntie is a SBer and saw that initial post.

 

[Thalassamania]

Being told that the Costa Rican diving public thinks I’m stupid and lazy because I use a dive computer made me think I was falling for a troll. Of course, I have used at least a half dozen different tables over my diving career and when planning a deco dive I still run the profile past the Canadian tables (DCIEM) so I guess I’m only half stupid.

I value the experience and wisdom of my diving elders. They have a great deal to teach us and their first hand knowledge of diving history is a treasure. We owe so much to those who went before.

HOWEVER….

Almost every advance in sport diving that made things easier and safer has been met with resistance from some elements of the diving community. Typically, this resistance is from the wise, old divers because new divers simply dive the way they are taught.

So let’s take a stroll down memory lane through those golden days of yore with a few quotes from elders of diving. These are things I was actually told by wise experienced divers over the years. The year of the quote is approximate but these are things I was actually told…


Early 1990s…
Dive computer? No way am I going to trust my safety to an electronic instrument immersed in salt water. I have my watch and my depth gauge. Dive computers will kill people.

True, the EDGE was the only dependable package and it ate 9 volt batteries like candy.

Mid 1980s…
Bouyancy jackets are crap. It’s just more junk they’re trying to sell to us. A properly trained diver with good skills can handle controlling his buoyancy.

Also true, I still dive my FENZY or no BC much of the time. I'm glad that you recognize that a diver with good skills can handle controlling his buoyancy without a poodle vest.

Early 1980s…
Alternate second stages are just another example of the manufacturers working with the training agencies to sell us more gear we don’t need. Buddy breathing has worked for the Navy for decades and they know what they are doing.

True also, though single hose regs did make it easier, especially when you had two buddies who were both OOA.

Late 1970s…
Do not put one of those stupid air gauges (SPG) on your breathing system! If the face of that gauge blows out you will lose your entire air supply. You stick to a J-valve. It’s tried and true.

SPGs were a good step, but some of the early ones did blow up and hurt people. J-valves, on the other hand often failed.

I didn’t even go into all stuff surrounding the advent of nitrox.


How did we ever survive....

You mean like:

The average recreational diver can't possible be expected to handle the critical learning objectives of a nitrox courseg without intensive training:

1. Breathe in.
2. Breathe out.
3. Control your depth and time.

 

[DiveNav]

Consider this (quite realistic) dive planning scenario:

The dive site is a pinnacle with a 100' bottom, rising to within 15' of the surface. The boat is tied to a mooring ball which is anchored to the top of the pinnacle. The operator tells you that time on this site isn't restricted, but they want you back on the boat with 500 PSI. It's your third dive of the day, you're feeling great and energized by the fantastic diving you've had so far, and you want a nice long dive of at least 90 minutes. During the briefing, you're also told that there's an octopus hole down at 60', and you and your buddy decide that you really want to check it out.
​

How do you plan a dive that allows you to safely meet all of these goals? ......

Give me the profiles of the 2 previous dives, surface intervals, tanks size, gas mix and your SAC .... and I will put together few alternatives for you in 2 minutes