Cruise rookie spends two memorable days on the biggest cruise ship in the world, and is wowed.

e’re going to mix and mingle.’’ With those words I settle into my stateroom, make a quick change of clothes, and get ready to see some of this ginormous cruise ship before we set sail.

What I don’t realise is we are actually going to Mix and Mingle, the two robotic bartenders at the Bionic Bar.

Welcome to Harmony of the Seas, the newest member of Royal Caribbean’s cruise fleet and described as their ‘‘biggest, baddest and sexiest’’ ship yet. In that regard Mix and Mingle make a wonderful first impression, nestled in the Bionic Bar on the Royal Promenade, one of the seven ‘‘neighbourhoods’’ on board.

You design your own cocktail, or choose from the menu, input the details into an app and watch Mix or Mingle do the rest. They even slice fresh lemon and lime and will shake or stir, or whatever. You choose, they deliver.

Moreover they tell you what they are doing at every step, via a big screen, which also has estimated waiting time between drinks, where your drink sits in the queue, and stats on the most popular drinks of the day, broken down by gender and age, too.

It’s a wow-type introduction to this ship, and being wowed develops into a theme on this short, two-day inaugural return cruise from Fort Lauderdale, Florida to Nassau, Bahamas.

There is colour, light and movement at every turn and a new experience at every corner. It’s like a theme park, water park, entertainment hub, sports complex, beach, shopping mall, restaurant/night club strip all in one, within a five-minute walk (and elevator ride) from each other.

Size

Nothing boggles the mind more than the sheer size of Harmony. At 362 metres long, it lays claim to being the biggest cruise ship ever built, nudging out sister ships Oasis of the Seas and Allure of the Seas by a mere 30cm.

We’ve all seen cruise ships docked in port somewhere and probably commented on how huge they look, but this is next-level material. For some perspective, Harmony houses a two-lane, 667m running track around the outside of Deck 5. That’s more than 1.5 times the length of an Olympic-sized athletics track. And, I might add, a highly worthy feature for those who need to burn off the previous night’s indulgence.

Despite being gigantic, there is still enough movement to remind you that you are on a ship at sea. It’s subtle, but you do feel some sway from time to time, which is just how it should be for those wanting an authentic cruise experience!

Ultimate Abyss

The size goes up, too. Harmony boasts 18 decks, 16 of which are guest decks. It’s that vertical size which allows for one of the most stunning experiences Harmony’s stun-factor, however, is not limited to her size, or high-seas rides. In fact the variety of entertainment and dining options – many of them unique – is possibly her crowning glory. on the ship, the Ultimate Abyss, a pair of 10-deck high tube slides which look like purple intestines.

Climb onto the see-through platform, 42m above sea level, grab your mat and jump in, then drop from Deck 16 to the Boardwalk on Deck 6 in just a few seconds.It’s an exhilarating experience that is akin to a rollercoaster in terms of the thrill factor. It also serves as a marvellous alternative to the elevators if you’re running late for the aqua show.

‘‘It was designed to scare you, and especially scare the kids,’’ Royal Caribbean chief executive Michael