Advice on SPG

[phoenix31tt]

To say "we were spared" is to deny the superiority of the metric system

agreed... and it's even worse for countries like us who are influenced by both sides... so some things are metric and some are imperial... we have to learn both -.-... wish they would just stick with metric... soooooo much easier and accurate

 

[bmlbytes]

I'll go against the grain a bit here and suggest you find an SPG that is marked for both Imperial psi and metric bar. It would help if you travel to other places in the world as well as show you have an eye toward the future when the entire Imperial system goes the way of the dodo.

As someone who hasn't done a dive outside the US, I am curious. What benefit does having both do for someone who learned the imperial system? It's not like anyone else is using your SPG, and if you know the imperial system better than the metric system, shouldn't that be enough? I am just having trouble thinking of a situation where you'd need the other system on your gauge.

 

[phoenix31tt]

As someone who hasn't done a dive outside the US, I am curious. What benefit does having both do for someone who learned the imperial system? It's not like anyone else is using your SPG, and if you know the imperial system better than the metric system, shouldn't that be enough? I am just having trouble thinking of a situation where you'd need the other system on your gauge.

when a crew or dive buddy who doesn't understand imperial asks?... can't see any other reason

 

[JohnnyC]

As someone who hasn't done a dive outside the US, I am curious. What benefit does having both do for someone who learned the imperial system? It's not like anyone else is using your SPG, and if you know the imperial system better than the metric system, shouldn't that be enough? I am just having trouble thinking of a situation where you'd need the other system on your gauge.

When I'm diving with DM's that only know imperial, I'm doing the conversion in my head when they do a gas check, it gets old. Most are happy with just an ok, but some are insistent. 100 bar is not equivalent to 1000 psi, so they automatically assume I'm almost out of air unless I put my spg in their face and show them the "bar" marking. At that point they generally look confused and just leave me alone. Even informing them pre-dive that all of my information is metric, they still act like they have no idea what's going on.

Unfortunately, since most of the friends I dive with are OW or AOW at most, I do less cave and technical diving, and more shallow reef diving these days so I get more crappy DM's.

 

[kwinter]

If you're happy doing single tank dives inside the U.S. your whole life, you'll be fine with a PSI gauge, cubic foot tanks and yoke valves. But if you ever imagine that you might travel for diving or get into anything technical, then metric will be a whole lot easier, especially if you go metric from the very start. I know how much oxygen I use because I'm diving a 3 liter tank that used 60 bar. Therefore I used 180 liters of O2. And I can divide that by my run time to get my consumption rate in liters per minute.
The metric system is superior in every way, and the U.S. can not pretend to be the leader anymore. The world has gotten very small and metric is the way of 98% of the world.


iPhone. iTypo. iApologize.

 

[eelnoraa]

From someone who started with metric until age of 16, then adopted imperial from 16-35 years old. I think the #1 importance is consistency. If the entire world is on imperial, I am OK with imperial. Same for metric. As to imperial vs metric, I do think metric is a more advanced unit system, just because everything works together better. For example, water has density of 1000kg/cubic meter. For very 10 meter increase in depth, pressure increase by 1bar, ....

The strange thing is US is one of the most technological/scientifically advance country. In all scientific measurement, metric system is used. I just don't understand why US population hasn't adopted the metric. Even Canada and UK( who invented the imperial) have switched.

 

[JohnnyC]

The strange thing is US is one of the most technological/scientifically advance country. In all scientific measurement, metric system is used. I just don't understand why US population hasn't adopted the metric. Even Canada and UK( who invented the imperial) have switched.

The foot is why. Because metric doesn't have a good intermediate measurement between centimeter and meter (nobody uses decimeters) you start working with either very large numbers in mils, or very large numbers in centimeters, or a combination of meters and large numbers in centimeters. It seems to be a purely psychological thing. We say 5 feet, not 60 inches. In metric, we say 1.52 meters. It would be like saying 1.66 yards. Because we've grown up with that intermediate measurement, for which most things in our daily lives are described in, it's hard to deviate from that. The foot is also a very useful measurement because it can be easily estimated precisely enough for use. You can step one foot in front of the other for a fairly precise measurement, or you can pace out a distance for yards, or divide by three and still have a close approximation.

The fact that metric math is easier makes no difference, to native users, saying 15 feet makes more sense than saying 5 yards, and definitely makes more sense than saying 4.6 meters. We just think in inches and feet. We need to make a change whereby a single generation completely switches to the metric system and stays there.

Maybe in the diving world it just sounds more impressive to say I went to 100 feet, instead of saying 30 meters. An we Americans, we like to be impressive.

 

[KevinNM]

The metric system is superior in every way, and the U.S. can not pretend to be the leader anymore. The world has gotten very small and metric is the way of 98% of the world.

"There are two types of countries, those that use metric and those that have put men on the moon." That said, I use a Bar SPG because it really is easier to do the math.

---------- Post added July 21st, 2015 at 11:18 PM ----------

I totally agree here. I have been looking for one but can't find it. If anyone has a source, please let me know.

Scubapro 2.1" dual pressure gauge I found it a little small and not as readable as the dive gear direct white on black gauge, but try it. I put it on my pony.

 

[kwinter]

The foot is why. Because metric doesn't have a good intermediate measurement between centimeter and meter (nobody uses decimeters) you start working with either very large numbers in mils, or very large numbers in centimeters, or a combination of meters and large numbers in centimeters. It seems to be a purely psychological thing. We say 5 feet, not 60 inches. In metric, we say 1.52 meters. It would be like saying 1.66 yards. Because we've grown up with that intermediate measurement, for which most things in our daily lives are described in, it's hard to deviate from that. The foot is also a very useful measurement because it can be easily estimated precisely enough for use. You can step one foot in front of the other for a fairly precise measurement, or you can pace out a distance for yards, or divide by three and still have a close approximation.

The fact that metric math is easier makes no difference, to native users, saying 15 feet makes more sense than saying 5 yards, and definitely makes more sense than saying 4.6 meters. We just think in inches and feet. We need to make a change whereby a single generation completely switches to the metric system and stays there.

Maybe in the diving world it just sounds more impressive to say I went to 100 feet, instead of saying 30 meters. An we Americans, we like to be impressive.

I think you would be shocked at how wrong you are regarding people's comfort level. I ask my students to estimate the distance from the building to the end of the parking lot. They have no clue. Not in feet or yards or meters. And if you really want a fun time, give people a tape measure. They might be ok with 38 inches, and maybe some would get the mixed measurement of 3 feet 2 inches. But what about all those little markings in between the inch numbers on a ruler? Fractions are a total mystery to most. And keep in mind these are college students. It is much easier for most people to measure 1.894 meters or even 189.4 cm. People deal with decimals all the time with money. The only ones dealing with fractions on a regular basis are carpenters and chefs. And they struggle with it too. I often had students who work in the trades take my class specifically to learn how to deal with fractions. It took less than a generation for people to be comfortable buying a liter bottle of Coke while they still buy a quart of milk. Bite the bullet and make the change. People will gripe and moan for about 8 congressional election cycles and then it will be second nature. But no one is willing to sacrifice those 8 elections.


iPhone. iTypo. iApologize.

 

[phoenix31tt]

So true @ fractions... Those 1/8 and 1/16 measurements etc people really have a hard time understanding... My father owns a wood working factory and you see it with workers all the time... They much prefer the metric... It's easier to read and count... He grew up mainly with imperial so for HIM it is easier... But it's easier for him to understand the metric than it is for them to understand the Imperial...


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---------- Post added July 22nd, 2015 at 10:40 AM ----------

oh not to mention when it's time to add two measurements :|