The 3rd week of Navy SEAL training or Basic Underwater Demolition/SEAL (BUD/s) is HELL WEEK. This part of BUD/S is absolutely grueling, not only physically and mentally, but also emotionally. It is a full week of intense punishment without sleep. The purpose of HELL WEEK is to weed out those who are not fully committed to becoming a SEAL and force them to either panic and quit, or stay and fight. HELL WEEK starts at "Break Out", which is solely intended to replicate the utter chaos of combat. After a relatively relaxing evening watching movies, the class retires for the night in anticipation of what is coming, but they don't know when. Sometimes the stress of the impending Hell Week Breakout causes people to quit early. Once the class has a full belly and asleep, comfortable and warm, the pandemonium begins. SEAL instructors rush into the barracks, kill the lights, and begin firing M60 machine guns with blank ammo, tossing flash-crash grenades and screaming at you through megaphones. The whole class is rushed out onto the main parade field, called the grinder because it is hard asphalt and filled with years of blood, sweat and tears. The class is then separated and alienated, one by one, while being sprayed in the face with freezing water from hoses, forced to dive through rubber boats filled with ice cold water and surrounded by continuous explosions, gunfire, and the disgusting discharge of thick smoke from grenades. Meanwhile SEAL instructors are coming at you from all sides, screaming and ordering you around, forcing you to bear crawl all the way to the surf zone to get wet and sandy, and then back to the grinder. This goes on for hours, almost to what seems like sadistic enjoyment from the SEAL instructors, but the actual point of Break Out, trains the men who remain with their class, to bond together, stay calm and focused, and to trust one another.