For DJs on the It's The Ship's line- up, it was not all work and no play.

They partied hard, just like the more than 3,800 people who were on the booze cruise, billed as Asia's largest music festival at sea, from last Friday to Monday.

Even at times when they were not scheduled to helm the decks, some played unannounced sets and joined one another at mini raves that popped up around the ship.

At the hot tub stage, there was a rolling carousel of DJs including Guatemala-born Carnage and Australia's Tigerlily who took turns at the deck, playing until 5am.

It was easy to get caught up in the mood during the four-day, three- night cruise from Singapore to Langkawi and back, aboard the Royal Caribbean International's massive Mariner Of The Seas liner.

Prices for tickets started at US$588 (S$832) each for a four- person cabin.

With a line-up of more than 50 international and regional acts, including heavyweights such as Dutchmen Ferry Corsten and Showtek playing across five stages, it was non-stop drinking and dancing daily from 2pm to about 6am.

Whether partygoers wanted standard big room electronic dance music fare, hip-hop or more niche stuff such as grime, It's The Ship had something for everyone.

No one seemed to care that American dance music collective Far East Movement had pulled out at the last minute and the line-up deviated from the schedule repeatedly.

The main stage was where you could sit in the pool or one of many hot tubs surrounding it and chill out with your friends while watching your favourite DJs spin.

Or you could people-watch. From men who looked like the Asian equivalent of Jersey Shore cast members to women in flower headbands and barely there bikinis, there was eye candy all around. The festival's Malaysian organiser Livescape Asia said there were more than 60 nationalities on board.

The first day saw Corsten and Showtek holding court at the main stage. Showtek were a crowd- pleaser and the biggest draw of the night, while Corsten was given a late set to cater to the trance crowd, which unfortunately had thinned out by the time he got on stage.

On the second day, the four-hour scheduled stop at Langkawi was not only delayed, but the sheer number of people waiting to disembark also saw hour-long backlogs.

Chartered buses took partygoers to a small, secluded beach with a main stage on which American DJ Kaskade played a headlining set of mostly conventional dance pop numbers from his 2015 album, Automatic. The most impressive thing was the pulsating visuals on the screens surrounding him and a trap-style remix of Adele's Hello.

But even before he came on, the alcohol ran out and many disgruntled people were seen heading back to the ship, where there was a non-stop supply of booze.

Day three saw everything from a block party in the afternoon with hip-hop acts to a Playboy party with a never-ending queue to main stage sets by Aussie Will Sparks and Canada's Adventure Club.

DJs mingling with partygoers was a common sight. You could catch Sparks at the breakfast buffet or trap music DJ Carnage shooting hoops on the basketball court.

While they took selfies with partygoers, most would show up unannounced at stages and hang out while their DJ friends played.

Apart from partying, there were fringe activities including a pilates class with DJ Tigerlily and a basketball tournament with American dance-R&B singer Brandon Beal.

The smaller stages were a great way to discover lesser-known acts.

British independent dance music label Black Butter Records, home to more major names such as Rudimental, was represented by the impressive deep house stylings of Applebottom, My Nu Leng and Woz.

Malaysian rappers Joe Flizzow, SonaOne and DJ Biggie were standout performers, dominating these stages with high-energy sets.

Set and activity times were laid out in newsletters in guestrooms every day, but no one probably looked at his watch, thanks to the event's free-and-easy nature.

If you chose not to pay US$40 (S$57) a day for patchy on-board Wi-Fi, you could be partying without distraction in the middle of the Malacca Strait. While It's The Ship had its hitches, it embodied the worldwide party people mantra of "eat, sleep, rave, repeat".