In March 1956, Ian Fleming and his friend Ivar Bryce accompanied Robert Cushman Murphy (with the American Museum of Natural History) and Arthur Vernay (with the Flamingo Protection Society) on a trip to Great Inagua in the south of The Bahamas to a flamingo colony. The colony was one hundred square miles of inaccessible mangrove swamp and salt flats, home to flamingos, egrets and roseate spoonbills: the location became the background for Dr. No's island of Crab Key. Much of the travel overland on Great Inagua was by a swamp vehicle, a Land Rover fitted with over-large tyres that became the model for the "dragon" used in the story. Fleming's inspiration for the Dr. No character was Sax Rohmer's villain Dr. Fu Manchu, the books about whom Fleming had read and enjoyed in earlier years. After returning from his nature trip, in June 1956, Fleming became involved in a project with Henry Morgenthau, III to collaborate on a television series Commander Jamaica, centred in the Caribbean with the main character of James Gunn. Although the project came to nothing, Fleming used the idea as the basis for the Dr. No novel. Fleming wrote the novel in January and February 1957 at his Goldeneye estate in Jamaica and initially gave it the title of The Wound Man.
As he had done in his previous novels, Fleming borrowed names from his friends and associates to use in his book; Ivar Bryce's housekeeper, May Maxwell, became Bond's Scottish "treasure" May. One of Fleming's neighbours in Jamaica, and later his lover, was Blanche Blackwell, mother of Chris Blackwell of Island Records: Fleming named the guano-collecting ship in Dr. No as Blanche. He later used Blackwell as the model for Pussy Galore in his novel Goldfinger and Blackwell gave him a boat called Octopussy, the name of which he used for a later short story.
After Diamonds Are Forever was published in 1956, Fleming received a letter from Bond enthusiast and gun expert Geoffrey Boothroyd, criticising his choice of firearm for Bond. Boothroyd suggested that Bond should swap his Beretta for a Walther PPK 7.65 mm, an exchange that made it to the novel. Boothroyd also gave Fleming advice on the Berns-Martin triple draw shoulder holster and a number of the weapons used by SMERSH and other villains. In thanks, Fleming gave the MI6 Armourer the name Major Boothroyd in Dr. No and M introduces him to Bond as "the greatest small-arms expert in the world".