He said it's unlikely that he will make rank and won't be allowed to stay in once his time is up. Knowing nothing about the Navy, we were all a little confused by this.
He is most likely in for 4 years. He should be rated as there are very few people without rates these days. Basically rated means he has a job title. Its very hard not to make E4 in 4 years. You have to be a complete drunk that is always in trouble.