SPOT Satellite Personal Tracker, The World’s First Satellite Messenger and Tracker
The SPOT “Satellite Personal Tracker” also known as the Spot Locator unit has more features and services than other Emergency Handheld GPS Personal Location Beacons.
Never be lost, stranded or be in potentially  life threatening situations in remote areas beyond the range of mobile phones.
Now, with Spot Satellite Messenger you can send a message for help or tell family members, friends or the emergency responders where to find you using GPS accuracy regardless of mobile coverage.  Help is just a push button away!
SPOT’s message and tracking functions enable users to send messages to friends, family or emergency responders, based upon varying levels of need and to visually track the location of the SPOT Satellite Messenger:

Costs

It uses AA lithium batteries that have a standby of approximately 12 months. It is light and easy to transport with coverage in Australia, Canada, Europe, Mexico, and practically, all of the continental United States sections of South America, Northern Africa, and North Eastern Asia.  This also has coverage in hundreds or thousands of miles offshore to these areas. 
There is a proven 99.4% reliability with the SPOT messenger system.  They process over 6 million messages a month or approximately 2.3 messages per second.  The SPOT network uses a GPS satellite system to verify a user’s location.

Optional unlimited tracking service will transmit your location to friends and family using Google maps every 10 minutes for a 24 hour period.  Tracking can be reactivated by the user of the spot unit by a press of a button.

GEOS Emergency Response Service

The SPOT Satellite Messenger has a life saving feature that many satellite phones do not carry.  The SPOT Satellite Messenger has four different functions.  One of these functions is the capability to alert a 000 service to your location in a life threatening event.  GEOS emergency response services are the providers of this function.   Here is how it works.  If you are in a life threatening situation you will press and hold the 911 button for 3 seconds.  This activates the service and will alert GEOS that you need help immediately.  They will try to get in touch with your first and second contact to establish that help is needed.  Your longitude and latitude is obtained through Google Maps™.  If your contacts do not answer the phone or if the second message comes through GEOS will alert the proper authorities to your location.  SPOT is accurate within a 20 ft radius.  So who gets notified when they are deployed?  When a signal is sent from land the local SAR (search and rescue) team, local police, or AFRCC (Air Force Rescue
Coordination Centre) are deployed.  If your signal comes from the sea the Coast
Guard is sent to your rescue.  While travelling abroad GEOS will contact the
Australian  Embassy.  No matter who comes to your rescue someone will be
coming.