A birdwatcher is on the lookout for a particular penguin, which left for sea about a week ago. He needs to catch it just as it returns to land, before it enters the colony to feed its chick. This is to recover the GPS tag glued to its plumage, which has measured a large number of parameters (dive depth, immersion time, water temperature and salinity, and above all GPS position). Cabane Guetteur, Ratmanoff king penguin colony, Courbet peninsula, Kerguelen archipelago.