The Best Ice Cream & Gelato on a Cruise

We all scream for: Gelato sandwiches and ice spaghetti at Cafe al Bacio & Gelateria

Where: Fleetwide (excluding Xpedition Class)

Why: The atmosphere of Celebrity's spot for coffee and sweets is reminiscent of a cosy European cafe. Along with on-the-house croissants and for-a-charge cappuccinos, passengers can purchase gelato and sorbet (the Italians call it sorbetto) by waffle cone or cup. (We like that even the smallest portion size includes up to two scoops.) What's not typically offered at your everyday gelateria are cookie gelato sandwiches -- with six cookie and flavour combinations -- or something called spaghetti gelato, which are elaborate sundaes: choices include an "Ice Spaghetti Pomodoro" (vanilla gelato with cream, fresh strawberry sauce and white chocolate) or "Ice Spaghetti Carbonara" (vanilla and hazelnut gelato with cream and chocolate-hazelnut zabaglione sauce).

Bonus: Oceanview Cafe, the free buffet restaurant onboard Celebrity Solstice, also makes ice cream and sorbet (made on the premises) available throughout the day, gratis.

We all scream for: Cold-slab, hand-blended ice cream creations at Cherry on Top

Where: Carnival Legend and Carnival Spirit

Why: Although it looks strange to have someone mix in ingredients to your ice cream as it's moulded by hand with scoop-like tongs on an ice-cold slab, it tastes so good. This concept has taken to sea onboard Carnival Legend at the Carnival's candy store, Cherry on Top. Pick from a dizzying, rainbow selection of bulk candy to blend right into your ice cream, for a fee. After you're done being a mad scientist of sugar, take to the outdoors to enjoy your creation in the open air. (Just watch out for some serious sun melt.)

Bonus: Available on Carnival Legend and Carnival Spirit, Shake Spot shakes it up with a tempting variety of milkshakes and spiders (floats) for kids and adults. For $A5, get the little ones a traditional shake -- or try a tropical take on the standard made with vanilla ice cream, pineapple juice and coconut syrup. Mum and Dad can opt for a spiked shake or float ($A10) in flavours like The Spirit of Kentucky (bourbon, caramel syrup and vanilla ice cream) or Dark and Stormy (vanilla ice cream in rum and ginger beer).

We all scream for: The cookies and cream combo from New Zealand Natural Ice Cream

Where: Pacific Explorer, Pacific Aria, Pacific Eden, Pacific Dawn, Pacific Jewel

Why: NZ Natural was introduced to P&O in 2012 and there is now an ice cream parlour on each of the five ships. The combination of ice cream and cruising is irresistible for guests with thousands of scoops of ice cream finding their way into cones, sundaes, milkshakes and thickshakes across the fleet each week. The parlours are located on the ships' pool deck and offer ice cream in a cup or a cone, or milkshakes and thickshakes that include up to five scoops of ice cream. The parlours also please the crowds with sorbet, frozen yoghurt and sundaes available with chocolate and caramel sauce, whipped cream and wafers. On Pacific Aria and Pacfic Eden, the outlets prove popular with those who want to sit and linger over a barista-made coffee and a snack. Guest favourites include Cookies and Cream, Chocolate Ecstasy, Chocolate Hokey Pokey and Vanilla. Items bought at NZ Natural are not included in the cruise fare: one scoop costs $A5.

We all scream for: Macadamia supreme

Where: Sea Princess, Sun Princess, Dawn Princess

Why: Princess Cruises is known throughout the industry for its dazzling Piazza, a place to see and be seen in an eye-catching atrium setting. Adding to the hang-out vibe, three of Princess's local ships now feature a New Zealand Natural ice cream parlour. No, it's not gelato, it's ice cream. But here's the scoop: both ice creams and sorbets are incredible.  Although the business began in Auckland in 1985, it is now offered in more than 30 countries around the world as well as onboard the local Princess fleet -- Sun, Sea, Dawn Princess (soon to be renamed Pacific Explorer). You will know you are on holiday when you grab an ice cream cone filled with Macadamia Supreme or Mocha Almond Fudge before beating a path to the pool.

We all scream for: Good ol' Ben & Jerry's

Where: Royal Caribbean's Voyager-class cruise ships; Crystal Cruises' Crystal Symphony and Crystal Serenity

Why: Sometimes you just need the name brand stuff, and two cruise lines carry Vermont's finest. Cruisers might know that Royal Caribbean is synonymous with Ben & Jerry's at sea (thanks to their hard-to-miss "cow butt cabin"), but many might not realise luxury cruise line Crystal Cruises also serves the gourmet ice cream in its Trident Ice Cream Bar (on Symphony) and Scoops (on Serenity). During the course of a single cruise, Crystal's ice cream joints will rotate about 20 flavours including low-carb options, non-fat yogurts and a dozen homemade sherbets. Freshly baked waffle cones, cookies, sundaes and shakes are also available; fresh berries are a topping favourite.

We all scream for: Handspun milkshakes at Waves Grill

Where: Fleetwide

Why: Oceania is renowned for its fine dining, but did you know the line also makes a darn fine milkshake? The casual, poolside Waves Grill is not only a go-to spot for burgers and barbecue, but has plenty of homemade gelato, made-to-order sundaes and thick, handmade milkshakes. There's nothing better than baking in the sun and then sipping a frosty shake -- with no added fees to kill the chill.

We all scream for: Chocolate meets gelato at Venchi Gelateria

Where: MSC Divina

Why: MSC's partnership with Italian chocolatier and gelato artisan, Venchi, brings more than 135 years of sweet experience to the cruise line's U.S. flagship, Divina. While flavours -- created in a specially designed onboard laboratory -- rotate daily, you really can't go wrong with Venchi's hallmark extra-dark chocolate or gianduja (chocolate-hazelnut). Indulge a la carte on Divina's Deck 14, poolside.

We all scream for: Traditional Italian delicacies at Gelataria Amarillo

Where: Costa Diadema

Why: We dare you to deny the charm of Diadema's revamped gelateria, complete with gumdrop ceiling, chocolate fountain and 18 flavours of gelato and ice cream. Partnering with Italian brand Agrimontana, Costa provides authentic gelato along with other sweets like macaroons and snow cones, straight from Italia. Scoops run about 1.5 euros. Priceless is the old-fashioned carhop element, as waiters don cheery aprons and ball caps.

We all scream for: Malts at Pool Grill

Where: Fleetwide

Why: On a line known for luxury, it's nice to just lay back and savour one of life's simpler pleasures: a malted milkshake. The Pool Grill on Regent Seven Seas offers high-brow cruisers the chance to hang by the pool and grab a snack, or in this case, a chance to gleefully gulp a milkshake made with old-fashioned ice cream and magical malted milk. Sundaes with custom toppings are also available for those who like dessert to be a bit more solid. The perk of an all-inclusive line is that these frozen delights are free.

We all scream for: Exotic gelato flavours at the World Cafe

Where: Fleetwide

Why: New flavours of gelato are available each day at World Cafe, Viking Ocean's buffet restaurant. Tart fruit flavours like a tropical blend make gelato or sorbet the perfect way to cap a lunch of handmade sushi or toasty paninis. During our sailing in the Mediterranean, we enjoyed a scoop of cassis, a popular flavours in the South of France, made from black currants. Taking it just a few steps to the outdoor Aquavit Terrace to enjoy with a view made it taste just a bit sweeter.