Sail boats are divided into the categories dinghy and keel boat. Dinghies have a skeg and can therefore capsize but not sink because the hull will float while capsized. The keel yacht can not capsize because the keel acts as a counterweight, however the keel yacht may sink if there is leakage due to too few buoyancy forces present. Exceptions are, for example, the unsinkable yacht models from Etap. A yacht with a keel (with ballast) is called either a keel yacht, sail yacht or just sail boat - although the term sail boat is also used for sailing dinghies.