small rubber boats on jagged rocks often in the middle of the night and one evolution is called brownproofing. they tie your feet together and then tie your hands behind your back and with your feet tied together and hands tied behind your back you jump into the pool. with your feet tied together at your hands tied behind your back you have to swim 50 meters. come back from swimming 15 meters and what they ask you to do is sink to the bottom of the pool. and then sink back down. the next thing they asked us to do, when they first told us we had to do it i actually laughed out loud because i thought they were kidding. the next thing we're going to take your face mask and throw it in the water. it will sink to the bottom of the nine foot section and with your feet tied together and your hands tied behind your back you will swim to the bottom of the full, grabbed a face mask with your teeth and swim back to the surface and back down five more times. when you have to do things like this the instructors would always call them evolution. the instructors would say the next evolution is drownedproofi