Drifters are continually being deployed from ships around the world. They last for approximately 400 days unless they collide with land (like an island) in the ocean, or their batteries fail. Each drifter is assigned a WMO ID # (World Meteorological Organization Identification Number) so the data can be archived. In 2005 the goal to place 1250 drifters on the ocean was reached. Now, as drifters go off-line they need to be replenished. These are the buoys that you can co-adopt as part of the Adopt a Drifter Program.