A cross-country flight in a glider consists of thermaling at minimum sink speed, then cruising at best glide speed or higher in the desired direction until enough altitude is lost that it is necessary to find another thermal. There are a series of internationally recognized badges to challenge a glider pilot to increase his soaring skills. The Silver Badge requires a 3,281-foot altitude gain, a five-hour flight, and a cross-country flight of at least 31 miles. The goals increase to the Diamond Badge, which requires a 16,404-foot altitude gain, a 186-mile flight over a pre-declared course, and a 310-mile cross-country flight. There are also soaring competitions with pilots in standardized classes of gliders competing against each other. Obviously an intimate knowledge of the weather is critical to successful cross-country flights in a glider, so glider pilots go far beyond the basics to learn how to determine the likelihood of making the desired goal.