Crystal's ocean ships are quite large for our 'Best of the Best' category, carrying up to 848 (Crystal Symphony) or 1,070 (Crystal Serenity) guests. Rest assured that, once on board, you will feel as if you are somewhere intimate and personal, with lots of small restaurants and bars, all with the personalised style of service you would expect in a boutique hotel.

The food is amazing, and the chefs have worked hard to introduce a range of unusual and exciting Modern Cuisine dishes alongside the classic menu, making for a memorable dining experience, in whichever of the various restaurants you choose to dine.

The advantage of having so much space is evident in the range of facilities on board, and the extensive and stimulating programme of activities. Entertainment is more varied, and of a higher quality, than you would normally expect on a ship of this standard.

Even the most restless traveller will find plenty to do on a Crystal ship during sea days, whilst itineraries are planned to feature plenty of overnights in port, with a varied and interesting range of shore excursions to suit all tastes.

Worth noting is that a low-key children's programme makes this line the ideal choice for families during holiday time - but there is sufficient space to ensure a child-free environment for those who prefer it.

The Crystal difference is also very much in evidence on board the lovely Crystal Esprit, a luxury yacht carrying just 62 guests, while the launch of Crystal Mozart in summer 2016 has well and truly raised the bar when it comes to river cruising; there is simply no other river cruise line in Europe right now that can match the ambition and the onboard delivery of Crystal.

Further developments include the launch of the intimate Crystal Mahler, Crystal Bach, Crystal Debussy and Crystal Ravel in 2018; the refurbishment of Crystal Serenity in 2018; the launch of a new polar-class expedition yacht, Crystal Endeavor in 2019; and three Crystal Exclusive Class ocean ships, with the first due to launch in 2022.