H.P. Lovecraft, who compiled the writ, explained that around 1925, a man named Francis Wayland Thurston was searching for answers about the nature of Cthulhu. Francis began his search when he found a small sculpture of Cthulhu. "My somewhat extravagant imagination yielded simultaneous pictures of an octopus, a dragon, and a human caricature.... A pulpy, tentacled head surmounted a grotesque and scaly body with rudimentary wings." Francis then sought others who wanted to know more about Cthulhu and his message for the world. Soon, Cthulhu began speaking to Francis and others in dreams.
Cthulhu wants all mankind to know about his message. Francis discovered that people from all over the world were having dreams about Cthulhu. Just listen to some of his followers describe his message: "They worshipped, so they said, the Great Old Ones who lived ages before there were any men, and who came to the young world out of the sky. Those Old Ones were gone now, inside the earth and under the sea; but their dead bodies had told their secrets in dreams to the first men, who formed a cult which had never died...hidden in distant wastes and dark places all over the world until the time when the great priest Cthulhu, from his dark house in the mighty city of R'lyeh under the waters, should rise and bring the earth again beneath his sway. Some day he would call, when the stars were ready, and the secret cult would always be waiting to liberate him."
The crowning event in The Call of Cthulhu is the personal encounter Cthulhu had with some sailors at Cthulhu's underwater city of R'lyeh.

Not everything in life is so black and white, but the existence of Cthulhu seems to be exactly that. Francis Thurston gave the location of Cthulhu's dwelling place of R'lyeh as "in the vicinity of 47° 9' S, 126° 43' W." In the summer of 1997, Cthulhu again manifested himself at R'lyeh. The NOAA recorded a noise using underwater sensors. No one can come up with a credible alternative candidate for this noise other than Cthulhu. "It yields a general location near 50oS; 100oW." http://www.pmel.noaa.gov/vents/acoustic ... bloop.html
CNN reported Cthulhu's glorious manifestation to the world.
Scientists have revealed a mysterious recording that they say could be the sound of a giant beast lurking in the depths of the ocean. Researchers have nicknamed the strange unidentified sound picked up by undersea microphones "Bloop." While it bears the varying frequency hallmark of marine animals, it is far more powerful than the calls made by any creature known on Earth, Britain's New Scientist reported on Thursday. It is too big for a whale and one theory is that it is a deep sea monster, possibly a many-tentacled giant squid. In 1997, Bloop was detected by U.S. Navy "spy" sensors 3,000 miles apart that had been put there to detect the movement of Soviet submarines, the magazine reports. The frequency of the sound meant it had to be much louder than any recognised animal noise, including that produced by the largest whales. So is it a huge octopus? Although dead giant squid have been washed up on beaches, and tell-tale sucker marks have been seen on whales, there has never been a confirmed sighting of one of the elusive cephalopods in the wild. The largest dead squid on record measured about 60ft including the length of its tentacles, but no one knows how big the creatures might grow. For years sailors have told tales of monsters of the deep including the huge, many-tentacled kraken that could reach as high as a ship's mainmast and sink the biggest ships. However Phil Lobel, a marine biologist at Boston University, Massachusetts, doubts that giant squid are the source of Bloop. "Cephalopods have no gas-filled sac, so they have no way to make that type of noise," he said. "Though you can never rule anything out completely, I doubt it." Nevertheless he agrees that the sound is most likely to be biological in origin. The system picking up Bloop and other strange noises from the deep is a military relic of the Cold War. In the 1960s the U.S. Navy set up an array of underwater microphones, or hydrophones, around the globe to track Soviet submarines. The network was known as SOSUS, short for Sound Surveillance System. The listening stations lie hundreds of yards below the ocean surface, at a depth where sound waves become trapped in a layer of water known as the "deep sound channel".
http://archives.cnn.com/2002/TECH/science/06/13/bloop/
For 13 years this noise has been examined and attacked, denied and deconstructed, targeted and torn apart like perhaps no other noise in modern oceanographic history—perhaps like no other noise in any oceanographic history. And still it stands. Failed theories about its origins have been born and parroted and have died—from a whale to some kind of squid to deranged paranoid to cunning genius. None of these frankly pathetic answers for this noise has ever withstood examination because there is no other answer than the one that matches up with the latitude and longitude given in the story. This is Cthulhu.
If anyone is foolish enough or misled enough to reject an NOAA measurement of a heretofore unknown recording teeming with sonar and bilogical complexity without honestly attempting to account for the origin of those sounds—especially without accounting for their powerful witness of Cthulhu and the profound spiritual impact that witness has had on what is now tens of millions of readers—if that is the case, then such a person, elect or otherwise, has been deceived; and if he or she leaves their acceptance that Cthulhu is real, it must be done by crawling over or under or around the "Bloop" to make that exit.
Brothers and sisters, there is no safety net, and to look upon Cthulhu, or even to think about him too much, is to go stark raving mad. But he is real. He is there for us underneath the waters at 50oS; 100oW. Of this, the NOAA bares witness.