Looking back 20 or so years ago, cruises were regimented and rather stuffy affairs with dress codes and rules at dinner dictating where you sat -- and when.

While there are still options for fans of 'traditional' cruising, picking the right line these days requires a bit more homework, as cruises are simply so much more diverse. Whether you're travelling with grandchildren, celebrating retirement or marking a special anniversary, it's important to choose the right ship. None bar cruisers on the grounds of advancing age -- quite the contrary -- but some older travellers don't particularly want to be cruising in the company of 800 or more schoolchildren or on a ship where nightlife, constant blaring music and riotous pool games are the biggest selling points.

If you like formal nights and fixed dining, no problem: there are ships to suit. Maybe you enjoy the dressy bit but want freedom to dine at your leisure. That's no problem either. Some cruises have themes -- bridge, for example, or walking or gardens or classical music. Many offer 'enrichment' classes, easy and unpatronising introductions to new computer skills, such as setting up a blog or learning to edit digital photographs. Many lines nowadays realise that age is not a barrier to adventure and include active, sometimes physically challenging, excursions. Some have entertainment geared very much to Brits of a certain age while others have contemporary standup and high-energy dance shows.

Which one's for you? Check out our picks.

Find a Cruise
1. Fred. Olsen Cruise Lines

Why? While other lines cast around for a younger following to fill their ships, Fred. Olsen is at ease with its role as a comfortable favourite for Brits aged mainly older than 65. The ships are a small and manageable size, with a sleek, classic profile. Dining and entertainment are geared to older tastes without compromising quality, and the line offers some genuinely great value themes and top-notch guest speakers. There are cabins for singles and, in the evenings, gentleman dance hosts.

Ship shape: The line has three smaller, older ships (Boudicca (refitted in January 2011), Braemar and Black Watch) and Balmoral (which joined the fleet at the end of January 2008). Black Watch was voted 'Best Small Ship for Entertainment' in the 2012 Cruise Critic U.K. Cruisers' Choice Awards. Although there are very few balcony cabins, accommodations are comfortable, and there's a wide choice for singles.

What's so special? The free Vistas enrichment programme includes cruises themed around music, dance, painting, wine appreciation, antiques and gardens, often combining lectures onboard with themed excursions (for which there is a charge). Flagship Golf cruises have a golf pro onboard who will arrange lessons and competitions on the ship and tee times at popular courses in port. Music and Laughter cruises carry guest entertainers and comedians, all aimed at British tastes.

Time out? Excursions are usually coach tours of a town, city or region, with the amount of walking and steps clearly spelt out. Another themed feature of Fred. Olsen Cruises is its long-standing association with Ramblers Holidays, offering walk-and-cruise voyages, booked through Ramblers Holidays and led by an experienced walking guide, who takes small groups off on long, often demanding hikes in each port.

2. Saga Holidays

Why? You can't even book a Saga cruise unless you are 50 or older, but those who have passed their half-century are allowed to take a companion aged 40 or older. The reality is that most passengers are well beyond 60, but they tend to be an active, enthusiastic and well-travelled crowd.

Ship shape: The line has two ships -- Saga Pearl II and Saga Sapphire. Saga Pearl II features 126 twin cabins, 42 double cabins and 25 twin or king-size cabins. Twenty cabins have balconies, while nine cabins have French balconies. A great selling point for solo travellers: Saga Pearl II has a whopping 60 single cabins -- that's almost 25 percent of the total number of cabins (253)! The ship reflects Saga's trademark style and ambience with traditions such as afternoon tea, ballroom dancing and cabaret-style entertainment.The 706-passenger Sapphire is Saga's first venture into a more stylish and contemporary-style cruising, while still retaining an essentially British feel.

What's so special? For starters, single cabins don't cost the earth. Saga ships are also praised for their high food standards -- don't miss the line's delicious afternoon tea -- and friendly crew. Gratuities are included in the price, so there is no end-of-cruise worry about tipping. Saga also takes the hassle out of getting to port by including a private taxi (U.K. only).

Time out? Excursions are a mix of the more traditional coach tours and active, experiential tours. Some of Saga's itineraries are extremely ambitious, and passengers join the cruises knowing they will be visiting some challenging ports with only the most basic infrastructure -- the kind of places where the experience is fantastic but things can, and do, go wrong. These include remote parts of Africa and lesser-known spots in Asia. Saga has its own foundation, the Saga Charitable Trust, and some excursions visit projects supported by the Trust.

3. Voyages of Discovery

Why? Voyages of Discovery is a top choice for adventurous, well-travelled seniors who want to get off the beaten track knowing they can come home to a comfy, unpretentious ship after a hard day's sightseeing.

Ship shape: The line has two ships: Discovery, which has no frills, offers fixed dining, low-key entertainment and formal evenings. Voyager, a ship that was built in 1990 and joined the fleet in 2012, attracts a slightly younger market of 45-plus, thanks to its more contemporary look and flexible dining options. Voyager has 35 suites (30 with balconies) and three restaurants with open seating, as opposed to a fixed-dining option. Lectures onboard focus on the regions in which the ships are sailing.

What's so special? With the out-of-the-way cruise itineraries to places like Central America, the Amazon and the Chilean fjords, and interesting lecture programmes that feature speakers from the military, historians, scientists and diplomats, expect a full house.

Time out? The focus is really on the itineraries, which include destinations like Iceland, Russia and the Amazon. Full- and half-day excursions focus on area highlights and may include lunch in local establishments. Some overnight excursions are offered.

4. Cunard

Why? With a pedigree going back to 1840, when Queen Victoria was on the throne, Cunard is the ultimate in tradition for those older than 50 who want to remember cruising as it once was.

Ship shape: The three black-hulled, red-funneled vessels -- Queen Mary 2, Queen Victoria and Queen Elizabeth -- all offer the same Cunard traditions, yet vary in size. QM2 is the world's biggest liner, while Queen Victoria and Queen Elizabeth are smaller, carrying 1,990 and 2,068 passengers, respectively.

What's so special? Passengers really stick to -- and enjoy -- the dress code and several formal nights. The emphasis is on elegance; a string quartet plays in the ballroom, and tea-time is a special occasion with white-gloved waiters. Plus, passengers in premium cabins (Princess Grill and Queens Grill) get their own a la carte dining rooms away from the maddening crowds. On Queen Victoria and Queen Elizabeth, they also get a private sunbathing deck. Dinner is at a fixed time in the main dining room, and open dining can be found in Queens Grill and Princess Grill.

Time out? Transatlantic voyages on Queen Mary 2 are the last word in relaxation, with six days at sea to do as little (or as much) as you want. Excursions on cruises other than crossings are more standard fare, usually coach tours, geared toward older passengers.

5. Cruise & Maritime Voyages

Why? The company operates from Tilbury, on the east side of London, which goes down well with travellers who don't want airport hassle. Cruises from north-of-England ports, including Liverpool and Newcastle, are popular with the local market there. The audience is mainly older Brits, and food and entertainment onboard are very much geared to a mature age group. Prices are extremely competitive, and as such, Cruise & Maritime attracts people curious to try cruising for the first time.

Ship shape: Cruise & Maritime has two ships: Marco Polo, an elderly vessel much loved by older cruisers for its stylish teak decking, gentleman dance hosts and deferential service, and Ocean Countess, also offering small-ship, traditional cruising.

What's so special? It's all about classic cruising -- fixed two-sitting dining, variety-show-style entertainment and G&T's by the pool. Prices are particularly competitive. Destinations are all places that can be reached from British ports; the line has a particularly strong Baltic programme, and it's well known for its Christmas markets cruises in December.

Time out? Excursions are tailored to older people who want to see the sights in comfort, so expect comfortable, guided sightseeing rather than hardcore adventure.

6. Swan Hellenic

Why? Traditional, cultural, British cruising is what Swan Hellenic is all about. It's part of the All Leisure Group, which owns Voyages of Discovery, Hebridean and Page & Moy, as well.

Ship shape: Swan Hellenic's one ship, Minerva, is a great pick for seniors, with its knowledgeable lecturers and interesting excursions. Minerva underwent a £10 million refit in 2012, which added balcony cabins and a new lounge, and increased deck space, creating an area for alfresco dining and rearranging the already impressive library. As well as a fly-cruise programme, Minerva also offers many ex-U.K. cruises out of Portsmouth, making it easy for passengers to get to the ship without the hassle of airports.

What's so special? Swan Hellenic's traditional feel and destination-led itineraries have continued to bring back passengers year after year. Excursions are included in the price, so although these cruises are priced higher than those of rivals, budgeting is easy. Passengers, although usually well over 60, make up an active crowd that's well travelled, highly educated and keen to explore.

Time out? Excursions are all part of the cruise fare, but there's no compromise on quality because of that. Swan passengers are usually equipped with great knowledge and will research destinations before they visit, expecting well-informed guides and thorough tours. Because the tours are included in the price, and because people take these cruises to discover new places, the ship tends to empty when it's in port.

7. Hebridean Island Cruises

Why? If it's good enough for royalty, it's got to be a winner with British over-55's prepared to pay for a bit of luxury.

Ship shape: The line has just one ship, 49-passenger Hebridean Princess, on which the Queen celebrated her 80th birthday. The ship sails the Scottish Highlands.

What's so special? Everything is included in the price, from drinks and excursions to tips. Dinner is served in one sitting. There are lectures by day when passengers are not ashore, and background piano music, poetry readings and whisky-tastings are offered in the evening. All in all, this is about as close to a country house party as it gets.

Time out? Just before the dinner gong, the cruise director will explain all of the details about the next day's excursions, from walking distances to toilet stops. Hebridean offers a series of "Footloose" cruises that focus on walking, with walkers divided into active and slower groups. Non-walkers are still offered the usual tours on these voyages.

8. Royal Crown

Why? Hebridean Island Cruises has branched out into river cruising with the ultra-luxurious Royal Crown, which has the same feel and ambiance as Hebridean Princess. Ship shape: Royal Crown carries just 90 passengers (and 30 crew), making it one of the smallest river cruise ships in Europe. Teak decks, arched picture windows and art deco-style rosewood and mahogany furniture give the ship an extremely elegant, classic feel.

What's so special? the experience of the Royal Crown is intended to compare with that of a private yacht, with passengers luxuriating in their sumptuous surroundings and enjoying cosseting service and genteel cruising.

Time out? Typically, shore excursions focus on local culture and history, with walking tours paced according to the slower passengers, visits to local vineyards and castles. Royal Crown also offers lavish bespoke excursions, such as exclusive tours of the Viennese Opera House, champagne lunches in the French countryside, and romantic boat tours along the canals of Amsterdam aboard the ship's beautiful teak sloop.

9. Voyages to Antiquity

Why? Voyages to Antiquity offers a single ship, Aegean Odyssey, exploring Mediterranean destinations of historical interest in summer and Asia in winter (from 2013). The whole experience is heavily geared toward culture and discovery.

Ship shape: Aegean Odyssey is an older ship, built in 1974, but it underwent an extensive refit in 2010. It offers bright, airy accommodations and a smart indoor-outdoor restaurant with alfresco dining in the evenings (in addition to the main dining room).

What's so special? The guest lecturers offer a high-brow series of talks, and most excursions, as well as wine with dinner, are included in the price.

Time out? Because tours are included in the price, there's heavy take up, and most passengers, who come from North America and Australia as well as the U.K., are happy to be ashore all day. Overnights in popular ports mean a chance to explore early, before the crowds, or to take special evening excursions like a private glimpse inside St. Mark's in Venice, for example.

10. Noble Caledonia

Why? Noble Caledonia offers a huge cruise programme, including ocean and river cruises, on a range of chartered ships -- but it also operates two of its own, 114-passenger Caledonian Sky (which joined the fleet in 2012 and once sailed for Hebridean as Hebridean Spirit) and its sister, Island Sky. Both attract a following of educated, adventurous passengers, mainly over 50 (due to a combination of high-end prices and the fact that there are no facilities for children onboard), looking for in-depth exploration with a degree of luxury.

Ship shape: Both ships are extremely comfortable, with extra-large cabins, cosy lounges and food of excellent quality. Each offers alfresco dining on the aft deck as an alternative to dinner in the elegant dining room. On expedition cruises, passengers are often ferried ashore to remote landings by inflatable Zodiacs. The less mobile should probably opt for itineraries where the ships dock alongside.

What's so special? Both ships offer a real house party atmosphere, encouraged by the fact that there's informal open-seating dining, wine included with dinner and excursions included in the price. Friendships are quickly formed. These are not ships for night owls; because everybody tends to be out on tour every day, many retire early, and evening entertainment tends to be a pianist in the bar. Guest lecturers travel with every cruise.

Time out? There's a comprehensive shore excursion programme, with almost all tours included in the price. Many are full-day and include meals at local restaurants, encouraging passengers to try local cuisine.