CLS (Collection Location Satellites) was created in 1986. The principle shareholders are the CNES and IFREMER (French Maritime Institute).
Argos is satellite system dedicated to protect and study the environment. It is based on a cooperation between France and the United States (CNES & NOAA): The CNES provided the payload and the NOAA provides and launches the satellites.
This cooperation is now extended to Japan (NASDA: Japanese Space Agency) and Eumesat (European Space Agency): These 2 new members will also launch satellites with an Argos pay load.
Argos has been operational since 1978 and its capabilities, as well as the quality of the service provided has improved every year since.
For ocean rowers, ORS has chosen the MAR YR Argos unit to track them. The MAR YR is waterproof, self powered for 90 days and floats.
In recent years CLS Argos has tracked most of the major yacht races they also track polar bears, birds, and fishing fleets, all over the world, and at any one time they are tracking thousands of beacons.
The reason most ocean rowers favour the CLS Argos system is because:

 it is independent of the electrics of the ocean rowboat,
 it tracks exactly the course of the rower(s) accuratley to within 150 meters, and
 it has an emergency signal capability.