The Royal Navy updated a famous WWII propaganda poster to warn its sailors about tweeting

US War Information Office/Royal Navy/Business Insider

An image showing the classic 1943 poster and its 2018 update side-by-side.

• British naval accounts are distributing an update of the classic 1943 "loose lips sink ships" poster.
• It warns "loose tweets sink fleets" - a reminder not to put sensitive operational details on social media.
• It shows the new HMS Queen Elizabeth carrier going down in flames.

The Royal Navy has revamped one of the most famous wartime propaganda slogans to warn its sailors to be careful what they tweet.

It issued an updated version of the 1943 "loose lips sink ships" poster, tweaked to refer to social media instead, and featuring the new HMS Queen Elizabeth aircraft carrier going down in flames.

The message was posted on Twitter Thursday morning by the official account of HMS Queen Elizabeth, along with a reminder that "OPSEC [operational security] isn't a dirty word!"

As the images above show, the new, Royal Navy-branded poster is an homage to a well-known 1943 propaganda poster distributed by the United States Office of War Information.

Instead of the 40s-style battleship shown sinking in the original poster, the 2018 version shows the Royal Navy's new Queen Elizabeth-class aircraft carrier, which is identifiable from the trademark "twin islands" design of its flight deck.

The message the poster is designed to convey is the same as in the '40s, though the media are different.

Getty Images

HMS Queen Elizabeth, with its distinctive "twin islands" design.

In WWII, commanders were worried that people with access to military information could carelessly share it in conversation, which could eventually be picked up by hostile intelligence services and used against the US military.

Today, the concern is that sensitive information could inadvertently be posted in public by somebody on board who did not realise the significance of what they were sharing.

It's easy to find images taken by people on board the ship on social media who tagged their location, though there's nothing obvious in them to suggest they could risk the ship's security.

Business Insider went aboard HMS Queen Elizabeth in December and spoke to sailors on board, including one who talked about social media.

Able Seaman Callum Hui, the youngest member of the ship's company, said that he uses networks like Snapchat to post photos to his friends back home - but that there are sensitive areas on board he knows not to document.

In a statement to Business Insider, the Royal Navy declined to elaborate on the specific poster campaign, but said it was part of a "robust" operational security plan.

It said: "The Royal Navy takes operational and personal security very seriously and robust measures are in place to ensure the security of the ship and the ship's company is not compromised."