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If
you do go EPIRB shopping, you’re going to find a lot of choices.
For one thing, as of last July, Personal Location Beacons (PLBs) were
approved for use in the United States. These portable units are capable
of a full 406/121.5 transmissions (see writeup on McMurdo Fastfind, opposite
page) and can be carried on land adventures like hiking and backcountry
skiing where calamities can have that same awful two-stage nature. Regular
EPIRBs designed specifically for boats have twice the battery life (48
hours), float upright, and are equipped with a strobe and, in Category
I models, automatically activate when they hit the water. However, Daniel
Karlson of NOAA’s SARSAT center says his agency doesn’t mind
that some boaters will opt for the flexibility and affordability of PLBs,
noting that in the situations when SARSAT is meant to be used, i.e. when
self-rescue or other communications like VHF are futile, a PLB is way
better than nothing.
Then there’s the
GPS business, and this is where the going gets sticky. Back in 1998 SARSAT
was modified so that a lat/lon position could be encoded into the 406-MHz
distress signal, meaning that rescue centers could get your nearly exact
position within a few minutes instead of the 30 to 90 minutes for a rough
position typical of the Doppler technique. Manufacturers like ACR and
McMurdo Pains Wessex began producing EPIRBs and even PLBs that either
interfaced with a GPS or had one built in. It sounds like a “must
have” option, but it’s also a technically tricky proposition.
GPS signals are notoriously weak, and an EPIRB with one inside, often
dubbed a GPIRB, has to do a cold start while possibly in rough water and
definitely in close proximity to RF transmissions. The alternative of
firing up a dedicated GPS, getting position, and then activating the attached
EPIRB or PLB may not be practicable, especially when the poop hits the
fan.
In the course of researching
this column, I discovered that the Coast Guard and NOAA, concerned about
the low number of successful GPS-assisted SARSAT calls, did some real-world
testing off Key West, Florida, last year. I’ve read the report, and
it’s disturbing. Some models seemed to deliver GPS position poorly,
if at all. But the report is also brand confidential and controversial.
Only ACR, proud of the apparent high performance of models like the GlobalFix
(pictured on opposite page), has identified its own coded test units;
other manufacturers say that the whole test procedure was flawed. I’ve
also spoken with experts who say that EPIRB and PLB certification standards
are weak, and hence we need to worry about claimed battery lives and transmit
powers. Ugh! I am not happy to report this possible messiness in what
I believe is an amazing safety system, but I can add some good news.
The Equipped to Survive
Foundation is planning on launching a better-designed program (with more
public testing), which will be sponsored in part by West Marine and the
BoatUS Foundation that may have taken place by the time this issue prints.
Everyone involved is hopeful that the Key West results turn out to have
been an anomaly, but whatever the outcome, I’ll at least summarize
the results in this column when they’re available.
For now I’ll close
with the words of NOAA’s Karlson: “Despite some current limitations,
SARSAT will really save your keister when needed.” However, this
tool has a lot of responsibilities that come along with it.” So true!
Shop carefully for an EPIRB or PLB, register it properly, and keep the
contact information current (both now possible online at www.sarsat.noaa.gov).
Then learn how to test it, how to use it most effectively—like giving
it a good sky view—and how to avoid false alarms (and what to do
if you don’t avoid them). Chances are good that you’ll never
need it, but...
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