BOA (Ballons sur l'Océan Austral) was a small balloon campaign carried out by the CNES and the LMD of the CNRS from the austral end of South America in 2000.

The campaign used superpressure balloons called BPCL (Ballon Pressurisé de Couche Limite) with a diameter of 2.5 meters and a total weight of 9 kg. They were adapted to perform long flights in the tropical and extra-tropical marine boundary layer, at a mean altitude of 1350 meters above the sea level. The payload was located inside the balloon and included sensors to measure along their trajectories pressure, temperature, water vapor and wind velocity (through successive GPS positions). The data was collected through the Argos satellite system.

The campaign was implemented in short time under the scientific direction of Robert Sadourny, with the technical aid of Bernard Dartiguelongue and the local support from the CIMA (Research Center of the Sea and the Atmosphere) from the University of Buenos Aires. The french-argentinian team used eight balloons left from the INDOEX campaign performed by CNES from Goa, India in 1999.

The balloons were inflated in an old hangar and hand launched (see picture at left) from an old airfield located in the outskirts of the city of Ushuaia, in the province of Tierra del Fuego, Argentine, during Febraury of 2000. The very severe meteorological conditions during the campaign were a hard test for the balloons as they suffered large thermal variations, a constant near-saturation of the air and icing conditions. The team had to devise a complicated launch strategy combining weather forecasts with balloon behavioural models to attain flights lasting merely around one week.

In all, of the eight balloons launched, seven made it's way to the Atlantic Ocean allowing for the first time to document the low-level circulation between 35°S and 60°S over the southeastern Atlantic.

Launch base	Date	Flight Duration	Experiment	Payload landing place or cause of the failure
Ushuaia	2/12/2000	4 h 10 m	BOA (Ballons sur l'Océan Austral)	--- No Data ---
Ushuaia	2/12/2000	1 d 14 h	BOA (Ballons sur l'Océan Austral)	--- No Data ---
Ushuaia	2/14/2000	5 d	BOA (Ballons sur l'Océan Austral)	--- No Data ---
Ushuaia	2/19/2000	1 d	BOA (Ballons sur l'Océan Austral)	--- No Data ---
Ushuaia	2/20/2000	3 d	BOA (Ballons sur l'Océan Austral)	--- No Data ---
Ushuaia	2/23/2000	1 d	BOA (Ballons sur l'Océan Austral)	--- No Data ---
Ushuaia	2/24/2000	1 d	BOA (Ballons sur l'Océan Austral)	--- No Data ---