There wasn't that many that couldn't swim when I went to Navy basic training. Those that could not swim would have to keep coming back until they passed the 3rd class swim qual. There are 3 parts to it and one guy failed one part when I was there because he got kicked in the head by another recruit. The swim instructors thought he was drowning and shoved the pole at him and he grabbed it. He just had to come back the next day to do it again and he passed. Even good swimmers can actually fail the swim test because you have to swim a particular way when your taking the test. If you do it different than what they expect they start yelling at you and if they aren't satisfied with your progress they will throw you the pole and you'll have to come back and do it again. As long as you listen to what they tell you to do and don't do anything that they didn't tell you to do you will be fine. That is actually the best advice about the whole boot camp process. Do only what they tell you to do, nothing more, nothing less. Don't "think" about it. If they didn't tell you explicitedly to do something then don't do it. Sorry about ranting on there, just trying to give you a little extra insight into the training. Good luck shipmate.