Tim,

I'm disappointed by you lack of knowledge. Your word carries weight as
an expert in these matters. Get expert. For example, 406 ELTs are dual
frequency, broadcasting on 121.5 as well. Suggesting that marine
EPIRBs are the same as Aircraft 406 ELTs is the worst kind of
obfuscation. While they take advantage of the same satellite
resources, the boxes themselves are very different. A sunset date for
121.5 satellite coverage has been set for February of 2009. As I've
noted, there are many other reasons the 406 units are better. These
are just a few. There are also diffences in
unit-to-satellite-to-receiving station visibility, accuracy, and time
to verification of signal. Not the least factor is the false alarm
rate, which introduces an adminstrative delay when any 121.5 signal
appears. Here's a snip from the SARSAT link.

"Different types of ELTs are currently in use. There are approximately
170,000 of the older generation 121.5 MHz ELTs in service.
Unfortunately, these have proven to be highly ineffective. They have a
97% false alarm rate, activate properly in only 12% of crashes, and
provide no identification data. In order to fix this problem 406 MHz
ELTs were developed to work specifically with the Cospas-Sarsat
system. These ELTs dramatically reduce the false alert impact on SAR
resources, have a higher accident survivability success rate, and
decrease the time required to reach accident victims by an average of
6 hours.

Presently, most aircraft operators are mandated to carry an ELT and
have the option to choose between either a 121.5 MHz ELT or a 406 MHz
ELT. The Federal Aviation Administration has studied the issue of
mandating carriage of 406 MHz ELTs. The study indicates that 134 extra
lives and millions of dollars in SAR resources could be saved per
year. The only problem is that 406 MHz ELTs currently cost about
$1,500 and 121.5 MHz ELTs cost around $500. It's easy to see one
reason for the cost differential when you look at the numbers.However,
no one can argue the importance of 406 MHz ELTs and the significant
advantages they hold.

Due to the obvious advantages of 406 MHz beacons and the significant
disadvantages to the older 121.5 MHz beacons, the International
Cospas-Sarsat Program have made a decision to phaseout 121.5 MHz
satellite alerting on February 1st, 2009. All pilots are highly
encouraged both by NOAA and by the FAA to consider making the switch
to 406!"