soft drinks on the Sea

Do they serve diet, caffiene-free cola on board or do I need to bring my own?

While I'm not 100% positive, I'd doubt they do. NCL serves coke products -- primarily coke, diet coke (w/ caffeine) and sprite. There may be a couple of other choices, but that's all I remember.

We've taken our own soda on board -- I drink Diet Dr. Pepper, my son prefers diet Pepsi, and my husband like Fresca. We've never had any problem taking a 12 pack of each on the ship, so to be safe, I'd just take your own.

[My2cents]

I drink only caffeine free coke and always take at least a 6 pack of my own. I even take one to the dining room at night if it sounds good. Never had anyone even give it a second look or cared.