Shannan Ponton.

Shannan Ponton from The Biggest Loser.

Want to meet your favourite celebrity? Find them at sea, writes Louise Goldsbury.

On Carnival Spirit this month, passengers can rub muscly shoulders with Shannan Ponton, the fitness expert on Australia's Biggest Loser. Appointed as Carnival Cruise Lines' first Aussie ambassador, he will be sailing with a big group of friends on March 21 to launch a new program of gym workouts for health-conscious cruisers.

Ponton is part of a growing cast of personalities enlisted by cruise lines to add some celebrity sparkle at sea.

Up close and personal: Rock The Boat's Mental as Anything.

Up close and personal: Rock The Boat's Mental as Anything.

These household names, from actors to former presidents, are invited to entertain people on the days in between ports of call. Since many special guests spend the whole voyage on the ship, they may also be spotted at breakfast, by the pool or in the bar.

Some cruises are officially hosted by a famous chef, radio presenter or television personality, who lead tours on land, throw cocktail parties or hold court at the dinner table. It is a chance for fans to hang out with their idols and experience a holiday that is out of the ordinary.

Australian cruises are starting to get in on the act, especially in the Kimberley, where competition is heating up between an expanding number of expedition vessels.

European river cruise companies, offering very similar itineraries, are also looking at ways to lure people to their brand. International ocean cruise lines, which attract the best-known names, are expected to announce the 2014-15 season's "famous afloat" later this year.

Just don't confuse a celebrity cruise with the brand Celebrity Cruises. According to a list of passengers' weirdest complaints, compiled last year by British travel agency Bon Voyage, one disgruntled female passenger demanded a refund after finding no celebrities on a Celebrity Cruises ship.

RAY MARTIN

Gold Logie-winning journalist Ray Martin and friend Ken Duncan, one of Australia's most acclaimed landscape photographers, will co-host North Star Cruises' inaugural Wet Season adventure in the Kimberley. The new 10-night itinerary between Broome and Wyndham is offered twice on the True North expedition vessel (March 26 and April 5) to capture the dramatic theatre of the outback monsoon.

See northstarcruises.com.au.

PETE EVANS

My Kitchen Rules judge Pete Evans hops on the 26-metre MV Great Escape in the Southern Kimberley on June 21. After catching fresh seafood in the Hunter River, the celebrity chef will prepare a dish of the day for each of the seven nights. Guests, too, can try to snag a barramundi on daily fishing trips. On such a small vessel, it will be easy to mingle with Evans during meals and on treks to Aboriginal rock-art galleries and swims under waterfalls.

See greatescape.net.au.

Peter Hillary, who has climbed the highest mountain on every continent, will swap summits for the sea when he joins a Lindblad Expeditions-National Geographic voyage of the Kimberley and Indonesia's Spice Islands.

The son of Mount Everest-conquering mountaineer Sir Edmund Hillary, he will talk about his experiences, including the time he was the sole survivor of a storm that claimed the lives of seven other climbers on K2. Passengers can also snorkel and dive at Rowley Shoals on this 15-day cruise, which leaves Broome on August 10.

See orionexpeditions.com.

JEAN-MICHEL COUSTEAU

Environmentalist and oceanographer Jean-Michel Cousteau will accompany several scuba dives from the luxurious small ship MS Paul Gauguin, as well as present lectures with videos of his work in the oceans. After a June 14 sailing from Fiji to Australia, he returns on October 25 for a Tahiti cruise to the Marquesas and Society Islands.

See wiltrans.com.au.

HELEN YOUNG

Author, journalist and long-term regular on 702 ABC's Saturday-morning gardening talkback show, Helen Young will impart her horticultural knowledge on a 14-night circumnavigation of New Zealand, departing from Sydney on November 21 on Holland America Line's Oosterdam. Sightseeing and garden visits are on offer in Dunedin, Akaroa, Picton, Wellington, Napier, Rotorua, Auckland and the Bay of Islands.

See travelrite.com.au.

ROCK THE BOAT

Music industry guru Molly Meldrum is set to present the biggest line-up of Australian rock legends ever assembled on water. The Angels, The Sweet, Mental as Anything, Richard Clapton, Angry Anderson, Jon English and Daryl Braithwaite are among performers scheduled for Rock the Boat 4.

In its fourth consecutive year, the week-long festival on Rhapsody of the Seas departs from Sydney on October 12 for nine nights of sailing around the south Pacific. Guests will have the opportunity to meet the artists and learn some new moves in dance lessons.

See rocktheboatcruise.com.au.

PERFORMING ARTS

The inaugural Bravo cruise brings together the biggest names in the performing arts, including Marina Prior, Elaine Paige, John Waters, Teddy Tahu Rhodes, David Hobson, David Alan Grier, Tommy Fleming, Guy Noble, Simon Tedeschi and Cheryl Barker and the Metropolitan Orchestra.

This seven-night South Pacific voyage on Radiance of the Seas, leaves Sydney on November 22.

Expect the region's best musicals, opera and theatre.

COUNTRY LEGENDS

Australia's hottest country-music stars are planning concerts at sea.

Cruisin' Country features John Williamson, Kasey Chambers, Shane Nicholson, Beccy Cole, Graeme Connors and the Bellamy Brothers.

This seven-night cruise on Rhapsody of the Seas, departing on October 5, visits Noumea and the Isle of Pines.

See cruisincountry.com.au.

AHOY!

A large resort ship carries between 1750 and 6500 passengers; boutique ships carry up to 250 passengers.

SIX MORE TOP CRUISES

DANCE UP A STORM

Holland America Line's Dancing with the Stars: At Sea is held in Alaska and the Caribbean, with six cruises featuring media personality Carson Kressley and the television show's professional dancers.

See hollandamerica.com.au.

RIVER CRUISE PARTY

The outgoing Australian of the Year, Ita Buttrose, heads to France in May for a river cruise, where she will host a cocktail party and conduct a question-and-answer session on Tauck's MS Swiss Emerald. tauck.com.au

CULINARY JOURNEY

Chef Luke Nguyen will guide walking tours and teach a cooking class in Vietnam on a 20-day Mekong package, with two departures offered on June 27 and December 26, 2014. See aptouring.com.au.

REEL DEAL

Film critic David Stratton leads a cinema-themed voyage from the UK to Iceland, Norway and the Faroe Islands, presenting talks and movies, on the Celebrity Eclipse on July 3. See travelrite.com.au.

COMIC RELIEF

Television comic Denise Drysdale is the VIP on a Celebrity Constellation cruise from Amsterdam to the Baltic via St Petersburg, departing on July 18. See travelrite.com.au.

CAROLS WITH RHONDA

Cabaret singer Rhonda Burchmore is sure to bust out the carols on APT's AmaVerde from Budapest to Amsterdam, departing December 21. See aptouring.com.au.