A lot of 'it depends' dude. But this is very generic...
In port: Officer's call at 7am. This is where the XO and department head (your boss) put out what the priorities for the day are, you deconflict issues with your fellow Divos in the department, and then meet with your Chief to figure out what your division is going to do that day. Then at 7:30 you go down and hold quarters with your division. You'll probably have a few meetings to discuss this or that (upcoming inspection, contractor maintenance work, ship's schedule, intelligence brief). Lunch/PT is probably from 11-12. In the afternoon you find the time to walk around your spaces, check in with Chief to see how that day's plan is coming together, BS with your guys while they're doing maintenance or cleaning up. Go talk to your dept head, let him know what's going on, what your division got done, what they're doing tomorrow, any issues he can help you resolve. You can expect to be walking off the ship at around 3-5pm (this is highly dependent on where you ship is in its life cycle, who your boss is, how efficient you are). At some point, hopefully you've found the time to study for one of your qualifications.
At sea: See above, but you're standing watch 5 hours on, 15 hours off - again this varies a lot, but 5/15 is a good entering argument. I spent 4 months of a 6 month deployment not standing any watch at all. I've also been stuck standing 5 hrs on, 5 hrs off for a one week underway - ouch!
Again, this is very generic. Not really a typical "day in the life" for most military careers I suppose.