5 The hairdresser, personal trainer, doctor or other service you may need is expensive - be prepared.
6 Some cruises have folk selling various products. If you're not interested in buying, make it graciously but firmly clear.
7 Shore expeditions are often expensive. On our cruise, a bus trip from a port to the city centre was $23 on the excursion, $5 if we had simply caught the local bus. Many shore expeditions expect a tip to be paid to the locals providing the service or guides. We found that wandering around the town centres was frequently interesting enough.
8 Do exercise! A surfeit of continually available food can not only strain the gut - there are always healthy options - but diminish your enjoyment of the cruise. On most cruise ships a three-time turn around the upper deck is about a kilometre and well worth doing at least once each day. Also, walk the stairs if you can - don't take the lift.
9 The casino is usually in the centre and you must pass through it several times each day. Know your limit and stick to it.
10 Recognise that you will be photographed repeatedly on the voyage and the prints will cost several times what you would pay on shore.
11 The increasingly popular art sales carry an unexpected premium over your purchase price that will be in the currency of the current ship - often US dollars. Your art work will need to be insured and professionally packed and couriered to your home or other collection point and could easily add hundreds of dollars to the purchase price.
12 Before using the internet check with their IT person as to systems and advice. You don't necessarily wish to download all your email traffic every time you open up - you will pay heavily.
13 Check your shipboard account regularly - you will see where you are spending your money.
Nevertheless I recommend a cruise - it is a really great way to enjoy a relaxed holiday.
Want more holiday inspiration? Sign up to our new Travel Insider newsletter here.
