Comment by Sam_Odio | Hacker News Reader

Comment by Sam_Odio | Hacker News Reader

I carry a PLB at all times in my vehicle [1]. In the US this device will summon rescue via satellite. I recommend it for anyone who spends time in remote areas. If you value your life at $1MM and there's a 1 in 3500 chance [2] that summoning emergency services in a remote area will save your life then this is a helpful risk-mitigating tool [3].

1. http://www.amazon.com/ACR-Electronics-ResQLink-Personal-Loca...

2. $280 / $1MM ~ 1/3500.

3. A useful metric might be 911 calls, of which there are 240 million in 2008[4], for the US population of 305 million. If you assume 5% of the calls are life-or-death, that your daily odds of needing to call in remote areas are the same as the country mean, that you spend 5 days a year in remote areas, and a 5-year useful life for the device, then there is a 0.2% chance the device will save your life.

240/310 * .05 * 5/365 * 5 ~ 0.002

4. http://www.911dispatch.com/info/fact_figures.html

Your statistics are seriously flawed. For example, your math in point 2 assumes you will certainly find yourself in a life threatening situation while carrying the device. And your point 3 probably vastly overestimates the fraction of life-or-death calls.

Your statistics are seriously flawed.

Actually, I think you a) misunderstood the claim in point 2, and b) take issue with the assumptions - not the math/statistics - in point 3.

your math in point 2 assumes you will certainly find yourself in a life threatening situation while carrying the device.

In point 2 the likelihood of a life threatening situation was not assumed or calculated (that's point 3). The conclusion, restated: If there's a 1/3500 chance you'll be able to effectively use the device to save your life, you're breaking even while mitigating risk.

And your point 3 probably vastly overestimates the fraction of life-or-death calls.

You've stated that I've made assumptions and you're right - which is why they're labeled as such. Feel free to suggest yours.

I carry one of those when I go backpacking. The satellite transmission they send to summon rescue includes your GPS position, and they also serve as short-range beacons to help rescuers zero in on you when they get close. That can be crucial if the PLB can't get a GPS lock, because rescuers might only know that you're located somewhere along miles of road or trail. If you're unconscious and out of site a few yards from the trail, the beacon might be the only way for them to find you fast enough to help.

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