"I booked a cruise to the Baltic, departing in June, almost a year ago. I have since been asked to pay a fuel surcharge. Is this legal?" Janet Henderson, Glasgow

Without sight of the exact contract you signed with the company, it's impossible to say for certain – but it's safe to say that the typical terms-and-conditions of the cruise companies includes a clause to say, basically, "If the price we pay for fuel rises, we reserve the right to pass that extra cost on to you."

The standard rule in the travel industry – as defined by Abta – is that any cost increase less than 2 per cent should be absorbed by the holiday company; and any increase above 10 per cent confers upon the client the right to cancel. You may not be surprised to learn that surcharges are almost always within the 2-10 per cent band. On a typical land-based package holiday, costing £500 per person, this could mean an additional £50. But cruises have a much higher average value, typically £1,000, and that implies a possible surcharge of £100.

So what are your options, besides feeling cross?

Reduce your spending on the cruise, most easily by declining the land-based excursions and sorting out your own days ashore; almost all the key ports, such as Tallinn in Estonia and Helsinki in Finland, have easy access from the cruise port to the centre. The one exception is St Petersburg, where the cruise terminal is a long and tricky journey from Nevsky Prospekt, the glorious main street. But this is also exactly the tour for which you need to sign up, because doing so circumvents the complex and expensive Russian visa rules.