Pros
Working in the Navy can be very rewarding personally as well as professionally. The Navy provides excellent benefits as well as predictable promotion rates to a certain point. There are lots of opportunities for increased education and a variety of interesting places where you can work.
Cons
First is the deployment rate. Navy ships are being deployed more rapidly than ever and you will have very little time to attend to your personal life. In a normal week it is very common to work more than 50 hours or more in a week, not including days when you will have duty, which is a 24 hour gig. Also, the salary increases quickly, but you will never have the opportunity to make as much money as you could in a different career. By the time you are a LT, the big pay increases stop. Also, sometimes you have little say in where you are stationed and when, which can be very difficult for families, a wife's career, etc.