A survey by Defaqto has warned holidaymakers to ensure that their holiday insurance is valid to cover any issues that may arise on a cruise holiday.

Having examined a wide range of single trip insurance policies that are currently on sale, Defaqto discovered that only 35% included cruise cover as standard – meaning people who didn’t check the small print would be at risk of incurring large bills in the event of a medical incident onboard.

In fact, more than 100 policies wouldn’t cover someone who was away on a cruise at all, with only half of those who did provide cover only doing so if they had been informed there was a cruise in advance.

Additional premiums also applied in many cases.

The survey also discovered that under 50% of policies would pay compensation for days missed on a cruise is confined to your cabin under doctors orders, with those that do pay our not going so far as to cover the cost of a cruise if you were taken ill for the majority of the trip.

“Travel insurance policies vary greatly in the level of protection they offer for cruises – and some don't offer cruise cover at all,” Defaqto’s head of insight Brian Brown said. “Therefore we urge anyone planning on setting sail on a cruise this year to double check their policy and ensure they have an adequate level of cover before they go away.

“Cruise cover goes beyond normal travel insurance, protecting passengers from incidents such as trip interruption, missed port departures, health assistance services wherever you may be in the world and so on, and it's vital that holidaymakers realise this before stepping on board. Otherwise they could be hit with unexpected bills on the return home.”

Things to ensure you do have in terms of insurance if heading off on a cruise include medical evacuation cover, extended cancellation cover and missed departure cover.

It would also be advisable to double check on any limits that apply to the period of travel given that cruises tend to take place over a longer period of time.