Google is asking millions of users to hunt for buried treasure using a new pirate-style "treasure mode" on its maps.
The company posted a video on YouTube describing how Street View's "underwater team" discovered a chest containing lost maps belonging to pirate William "Captain" Kidd during an expedition to the Indian Ocean.
The video explains how hidden treasure symbols can be unearthed on the maps, which have been digitised by a special 3D nanoscanner.
Google marketing manager Mike Pegg says: "The map is rumoured to contain the clues to Captain Kidd's long lost treasure, however the map contains encrypted symbols and codes and is not readily decipherable.
"Therefore, we're introducing treasure mode on Google Maps and inviting the whole world to come together in the search for clues."
The digitised 'treasure mode' mapsThe treasure mode - accessed in the top right-hand corner of the Google Maps window - includes a telescope-style Street View function, with sepia-tinged images of streets across the globe.
Google claims hidden symbols can be uncovered by shining sunlight on a computer screen, by joining phone and tablet maps together like a puzzle, or even by heating a laptop over the hob.
The company's contribution to April Fools' Day follows last year's prank, when it claimed an eight-bit version of Google Maps had been developed for Nintendo's NES games console.
Google also released a YouTube clip ahead of April 1 declaring that the world's most popular video website would shut down at the stroke of midnight.
The three-minute video, intended as a gag, described how the website would wind down as some 30,000 technicians began to trawl through 150,000 clips to select the world's best video.
A computer user has a sniff of the 'Google Nose Aromabase'"Gangnam Style has the same chance of winning as a video with 40 views of a man feeding bread to a duck," YouTube CEO Salar Kamangar declared, referring to the viral sensation from Korean pop artist Psy that is now the most-viewed video on the site.
Google's video also featured intense discussions between judges, who hotly debate the merits of everything from Citizen Kane to "epic skateboard fail".
While clearly tongue-in-cheek, several YouTube viewers appeared stricken or dumbfounded, while others expressed sadness and regret in attached comments.
Google also added a "Google Nose" feature to its search facility, boasting that it had created the largest ever database of smells that could now be accessed through a computer screen.
Searching the "Google Aromabase" brings up results such as "baked tarmac, lost luggage" in a search for "airport terminal".
The feature was also introduced in a YouTube video, with Google experts explaining: "What does a ghost smell like? Google Nose!"