In 1906, the RMS Adriatic became the first passenger ship to feature a swimming pool. Operated by the White Star Line, the pool was part of a suite of upscale amenities, marking a shift toward luxury-focused ocean travel.

By 1912, the RMS Titanic followed suit with its own heated saltwater pool (pictured). Though small by modern standards, the idea of swimming mid-Atlantic felt wildly extravagant and helped cement the Titanic’s reputation as the height of luxury.

Secrets of the Titanic: life on board the world's most famous ship

Amazing facts about cruise ships you might not know