Cruises: Do cruise ship doors actually lock – how safe is a cruise holiday really?

However, around 90 per cent of all cruise liners are fitted with some form of VingCard entry card system.

The first customer for the system was Crystal Cruises and VingCard has also supplied systems for Hurtigruten.

A Saga Cruises spokesman told Express.co.uk: “We have automatic Ving-Lock doors (key card) for all passenger cabins.”

According to door opening solution company ASSA ABLOY, VingCard’s new Gangway Control System takes the security system a stage further by linking all access doors to a central control system on the ship’s bridge.”

“In an emergency, such as a fire or the threat of boarding by unauthorized personnel, all external doors can be unlocked or locked at the flick of a switch,” said ASSA ABLOY.

Cruise travel does, however, remain a safe way to travel. A Cruise Line International Association (CLIA) spokeswoman told Express.co.uk: “A cruise holiday remains one of the safest forms of travel. Cruise ships today are the safest that ever sailed, thanks to the rules, regulations and technological innovations that govern their design.