Worst-Case Shopping
by Jeff
Image text: Wait a minute. If I'm escaping from a submarine at 50 meters, then I'll *definitely* need a flashlight to find air pockets for gradual decompression on the way up. Time to start shopping professional dive lights.
In this comic, Cueball is dreaming up reasons he should get a flashlight that is water resistant up to 40 meters instead of 10 meters. (As an aside, I think the same things when I'm shopping for watches... why the heck would I need it to to be water resistant over 10 feet?)
In the dream sequence over the first 2 and a half frames, Cueball appears to be escaping from a submarine or ship or some crash and diving 8 meters to find a key. His flashlight goes out at 10 meters because he bought the "Hi-Brite" model. Also, for some reason, the dream sequence references a "radio shed", which were only really used in the past for ham radios. I'm not sure why Cueball's dream sequence involves going into the past where radio sheds would be more prevalent.
The image text takes Cueball's thought process to the next level, because if he is getting a flashlight that works to 40 meters, he should probably be prepared for even deeper waters as well.
June 8th, 2011
Submarines are not typically pressurized. Once he leaves the submarine, he would not breathe any compressed air. The air in his lungs would expand at he ascended (Boyle’s law). He would not need to make a decompression stop.
June 8th, 2011
As he exits, the water will fill the chamber and compress the air he is breathing until he can swim out through the door – thus his lungs will be filled with compressed air which he will need to exhale as he ascends or risk a rupture. But there won’t be enough time for the nitrogen concentration in his blood to build up to the point where he would need to have decompression stops as Sammy notes.
June 8th, 2011
Correct, you exhale on the way up. The bends is not a concern.
http://en.wikipedia.org/wiki/Submarine_Escape_Immersion_Equipment
June 8th, 2011
Cueball is not escaping a submarine in the dream sequence. The badguys captured him after they all narrowly escaped a helicopter which was crash-landing into the water and which held the key to the shed. While they held him captive, they told him their diabolical plan. Cueball has escaped and needs to warn the president of their diabolical plan. His trusty diving watch tells him his depth as he descends. Just as he finds the wreckage and the key, disaster strikes again, only this time brought on by the heroes own folly in classical tragedy style.
June 8th, 2011
About the “shopping for watches”. The indication “water resistant to 50 meters” is an indication of how much pressure it can handle. If you dive into the pool it can be the equivalent of 50 meter of water pressure.
June 8th, 2011
Yeah, if your pool is 50 meters deep…
June 8th, 2011
I believe Emiel is referring to the pressure on the watch at impact when diving into a pool, not the pressure on the watch when submerged at the bottom.
June 8th, 2011
had a “water proof” watch many years ago, supposedly rated to 10m — after wising the Amazon Jungle for a few months I started to noticing pockets of damp on the inside of the glass, and the watch finally failed.
When sending it back, the manufacture claimed that I had deliberately damaged the watch by exceeding the 10m limit …. so much much for “water proof”… The 50m option may actually be better quality and therefore better value
June 8th, 2011
… In case I need to explain, the Amazon Jungle have close to 100% humidity at all times, whether rainy season or not.
June 22nd, 2011
It’s not the depth, it’s the motion. A watch rated to 50m is designed to withstand static pressure, just being there, not dynamic pressure, like being moved around. If you’re wearing a watch while swimming in the pool at 5m depth, it’s getting more than 5m’s worth of static pressure on it, as the motion temporarily creates greater pressure.
June 8th, 2011
Actually the numbers for watches are not to be taken literally at all. They are exaggerations grandfathered in.
This is the reading guide for water-resistance watches:
10m – is waterproof in mild rain
20m – is waterproof in rain/showers
50m – can be splashed with water
100m – is actually waterproof, but only until 5m, for more buy a divers watch.
June 9th, 2011
Nice… I never knew that, but it makes sense…
http://en.wikipedia.org/wiki/Water_Resistant_mark#Water_resistance_classification
June 8th, 2011
I’m not a big gamer, but Randall is. . . and in Fallout 3, there is a sunken ship, and a locked shed. Can any of you tell us if that is related?
June 8th, 2011
Does anyone else see a katana in the first frame?
June 8th, 2011
The title indicates that this comic is about the worse case scenario for shopping, whereby you wonder if you’re making the right choice, and considering the setbacks if you do not buy the more expensive one. The image text implies that by continuing this trend, you will never buy anything, therefore:”worse case shopping.”
June 10th, 2011
Kinda reminds me of another thinking-too-hard comic… http://xkcd.com/761/
June 11th, 2011
Just a FYI, radio sheds are still fairly common among ham radio operators.
June 11th, 2011
Also, I forgot to note – the radio shed in question contains ham radio equipment, which our “hero” could then use to warn the president.
June 15th, 2011
“Radio shed” = RadioShack, a chain of electrical supply stores in the U.S.
September 19th, 2011
Radio Shed = Radio Shack… but where do you think the store got their name from? The “radio shack” is traditionally the building at the bottom of the transmission tower. Most of us in the business still use this reference when talking about the power requirements, HVAC and cable entry for the said “shack”. Of course, in this comic it was simply a reference to broadcast his warning (whether HAM or not). I think most serious HAM radio fans might have actually had their own “radio shacks” because the rest of the family banned them from being in the house