If you could change one thing about the dive industry, what would it be??

[TheRedHead]

That's interesting. On what basis do you make this claim?

fsw
symbol for "feet of seawater," a conventional unit of pressure. 1 fsw = 0.3048 meter of seawater (msw).

msw
symbol for "meters of seawater," a conventional unit of pressure. The pressure exerted by seawater varies slightly with temperature and salinity, but for practical purposes the convention is that each meter imposes a pressure of 0.1 bar or 10 kilopascals (about 0.102 kilograms of force per square centimeter or 1.45 pounds per square inch). Sometimes the convention is that each meter is equivalent to 0.1 atmosphere (0.1013 bar), which is practically the same thing. In English units, 1 msw = 3.28 feet of seawater (fsw). Underwater pressure gauges are frequently calibrated in this unit.

See: http://www.unc.edu/~rowlett/units/dictM.html#msw

I think we learned this on OW class, but it makes perfect sense as a foot in sea water is the same as a foot in fresh water as a measure of a distance, unless you are traveling at speeds approaching the speed of light. But I see it misused all the time by shops describing classes:

Training dives for Advanced Open Water classes will not exceed a depth of 100 FSW. Training dives for Junior participants will not exceed a depth of 70 FSW.

http://www.divesports.com/advopenwaterclass.htm

Students must complete four (4) Open Water dives and remain underwater for minimum of fifteen (15) minutes on each dive, for a total of 80 minutes.

Training depth must be between six (6) msw and eighteen (18) msw / twenty (20) fsw and sixty (60) fsw.

http://www.nitroxdiver.com/Training/OWdiver-std.html

 

[TheRedHead]

So do I. The metric system actually makes sense, which is something I cannot at all say about the imperial system. I can understand Walter's comment since imperial is something us Merkins have grown up with and are just used to, but it really does not make any sense at all. It's a tragedy it still exists.

I think it makes a lot of sense in diving considering the origin of the metric metre (or meter) and the origin of the imperial foot:

One meter is defined as being equal to 1,650,763.73 wavelengths of the orange-red line (corresponding to the unperturbed atomic energy level transition between levels 2p10 and 5d5) in the spectrum of the krypton-86 atom in a vacuum.

Our modern measurement of 12 inches equaling 1 foot actually comes from a king’s arm. Or, to be more precise, one-third of a king’s arm. According to Isaac Asimov's Book of Facts, the arm under discussion is that of King Henry I (1068-1135) of England, who had a thirty-six inch long arm and decreed that the standard “foot” should be one-third of that length.

We take arms with us when we dive and even use "arm spans" in navigation. Which is more intuitive and makes more sense?

 

[pants!]

I was born and raised with imperial, but 1 cm is easier for me to visualize than 1 in. Also, 12 inches is as random as 30 cm, but both are about the same. I have no problem visualizing a meter, a liter, or anything else.

If you want to argue definitions, the current US definition of an inch and pound are based on their metric counterparts, which are actually defined by natural relationships instead of a dead king's arm.

An arm span is 6 feet, or..... 2 meters. Neither is harder than the other.

As someone who has worked quite a bit with both systems, and traveled enough to have used both systems a good bit, I can without reservation say that metric is superior to imperial in every conceivable way*.


*except temperature. The F scale is much more relevant to everyday life than the C scale. 0F is "very very cold" and 100F is "very very hot"... in fact, both are about the usual extremes people generally encounter, with "below 0" meaning "exceptionally cold" and "above 100" meaning "exceptionally hot"... with everything in between. On the Celsius scale, you have to hit -15 or -20 before you get "very cold" and "very hot" is something like 30. 0 is "kinda brisk"

 

[Walter]

Ya gotta admit, the one good thing about temps reaching -40 is you don't have to ask which system is being used.

 

[ranger979]

a) Use something besides models in bikinis to sell people on scuba.

Come on - this is one of the best parts of scuba.

 

[PhotoTJ]

Seen the Sept issue of Scuba Diving? Jessica Alba on the cover. You can hate and despise it all day long, won't change anything, sex sells. A nice alliteration; Sex Sells Scuba.

 

[WarmWaterDiver]

I was born and raised with imperial, but 1 cm is easier for me to visualize than 1 in. Also, 12 inches is as random as 30 cm, but both are about the same. I have no problem visualizing a meter, a liter, or anything else.

If you want to argue definitions, the current US definition of an inch and pound are based on their metric counterparts, which are actually defined by natural relationships instead of a dead king's arm.

An arm span is 6 feet, or..... 2 meters. Neither is harder than the other.

As someone who has worked quite a bit with both systems, and traveled enough to have used both systems a good bit, I can without reservation say that metric is superior to imperial in every conceivable way*.


*except temperature. The F scale is much more relevant to everyday life than the C scale. 0F is "very very cold" and 100F is "very very hot"... in fact, both are about the usual extremes people generally encounter, with "below 0" meaning "exceptionally cold" and "above 100" meaning "exceptionally hot"... with everything in between. On the Celsius scale, you have to hit -15 or -20 before you get "very cold" and "very hot" is something like 30. 0 is "kinda brisk"

I too have worked somewhat with both Imperial and Metric (SI) systems, but I find the US system is generally the most practical for my everyday use.

You evidently haven't been involved in the global exploration for, production of, transportation of, or buying and selling of, crude oil. The standard is still the good old US Barrel - based on 42 US Gallons (not Imperial gallons). The Imperial gallons and many other items of the imperial system never really made sense to me, but I don't find the metric system 'superior in every way except temperature'. There are several other such applications where the US system is more conveinient for every day use, such as pressure in PSI rather than kiloPascals, heat energy in BTU's or MMBTU's (such as methane - having 1000 BTU's per standard cubic foot - nice round number) rather than Calories / KiloCalories, or Joules / MegaJoules.

You might as well put temperature on the Rankine scale if you really want it the scale used to 'make sense' - defining 'absolute zero' as just above minus 460 degrees Farenheit doesn't really make sense.

But, to each their own - thankfully there isn't a 'law' requiring any one specific system (yet) here in the land of Liberty, so everyone is free to convert to whichever system they're most comfortable with.

 

[cpe111]

Hmm - my post wasnt intended to spark a debate in the merits of metric vs. imperial (pick a system) - intersting as though that may be in itself.

Ultimately though, its all about getting people speaking the same language and thus eliminating confusion. There'd be less satellites flown into asteroids if we all used the same unit of measure. When someone referrs to a gallon - which imperial system are you referring to, because not all gallons are the same? When someone uses a ton - is that a long ton,a short ton or a metric tonne etc.

As far as people being comfortable with a system, generally people are comfortable with whatever system they were brought up with and exposed to. The key here is exposure - you become fairly adept at conversion once you see both systems side by side every day. Even then, as you pointed out, some aspects of either system may make more sense on one system to the other for a particular purposes. But i think in general, metric does make more sense - it is more consistent with definitions for most measures having clearly defined, simple relationships.

The UK converted from Imperial to metric for most things. The process has taken over 20 years and is still ongoing, as far as i am aware there are still no plans to use kilometres instead of miles.

Unfortunately today, with dual systems in common usage, despite the merits of one system or another, there will always be the possibility of confusion.

 

[WarmWaterDiver]

The US gallon is *not* part of the Imperial system by definition - the Imperial gallon is. The US gallon is not the volume occupied by 10 pounds fresh water. Is there an Imperial *barrel of oil*? I've never seen such a unit. This was my point on the US system being neither Imperial nor metric (SI).

Can you convert in your head the deadweight tonnage (spelled like this) of a one million US barrel cargo capacity supertanker? Or, in your head, how many cubic meters capacity by volume a 5 million barrel ULCC (Ultra Large Crude Carrier) can contain in its cargo holds?

So, if you haven't worked with the US system, you might give it a try, as at least a challenge in a Foreign Language type exercise. I have personally worked with all 3 systems, not just your two mentioned. There is a wider world than you evidently have worked with, in a *one world* effort.

And, if folks crash spaceships etc.because they aren't competent, it doesn't matter what system of measure one uses. I wouldn't want them working as a teller at my bank, much less playing with the all too easily spent taxpayers money. One of my most practical lessons received from any instructor (who was not in the world of academia, but an up-through-the-ranks veteran employee now performing a training role) was "First check your calculations to see if they are reasonable. If they are not reasonable, there is no way they can be accurate!" The latest issue of a US Engineering Honors Society magazine had a very interesting article from someone themselves in the world of academia about culture the last say 10 or so years rewarding mediocrity through the schools, and instructors expected to continue this practice in college, to enhance 'self-esteem' of the youth, and what price that eventually puts us all paying. I don't think a *universal* measurement system could ever cure that.


OK - now for my take on the thread title, for my "One Thing", I'd get rid of all the restrictions about not allowing stuff sold on the internet or by mail etc. to qualify for warranty, service, etc. Obviously, there are companies who do not have this policy that are still quite successful, both in the scuba industry and not in the scuba industry. And some who have changed over the years - how long ago was it that one could first buy Dive Rite equipment via telephone / mail / internet and still have full warranties? Not too long ago as I recall - maybe 3 years or less. But now, no problems from their authorized dealers (Dive Rite Express and Scubatoys to name two I know of). So, if this was such a 'terrible thing' for the industry, why would a tech oriented company like Dive Rite change to accept this if safety was really the crux of the matter?

 

[FOUNDATIONER]

I can rebuild the braking system on my car and go flying down
the interstate to my hearts content, but I can't get parts or
service manuals to rebuild my regs. Oddly enough all the tools
to do this are easily available. I LIKE servicing my own brakes,
for when I am finished, I KNOW my car will stop.
I know, not everybody is capable of servicing their own brakes,
thats why there are auto technicians.
My LDS does a fine job of taking care of my annuals, but I would
much rather be doing it myself.