Sea time is really hard to predict these days. The "Shooters" ie DDG, FFG, etc have a saying, "It's Friday, time to get underway!". I served on two Amphibs, both LPD class; in four years, did two 6+ month deployments, with 2-4 week underways about every month and a half other than shipyard periods (this is a total crap-shoot, could be 3-12 months, but you work from 5am to 6pm, so no real difference). I guess just off the cuff, we spent well over 70% of the year at sea. From what I know of carriers, they deploy longer, but may spend a little more time in port. from what my friend on the GW said, liberty ports were rare, but not any more so than when we were both in the Gator Navy. When you factor in duty days (up to every third day on a smaller ship), which is even worse than being underway at times...it's a challenge to find ways of "enjoying" sea duty. The good thing is, when you look at civilian careers, how often do you land a job making up to 40K, with 30 days paid vacation a year, and annual business trips to exoctic places? I've been on the civ side long enough to get bored.