Bulova has been manufacturing fine watches since 1911, 36 years after Joseph Bulova came to the United States from Bohemia and started a jewelry store. Bulova watches have become a prize collectible; if you are interested in purchasing one, you will want to know if it's the genuine article, given all the knockoffs available.
Look at the face of the watch. Many Bulovas have the name "Bulova" in the face somewhere, or on the metal exterior. The various brand names, such as Marine Star, Caravelle, Accutron and Wittenauer, sometime appear with the company name -- or instead of it.
Input the serial number into the interface on the Bulova website. Many recent models have a serial number on the back that you can type in to see if it is a real Bulova.
Turn the watch over and look on the back. If your watch was made between 1924 and 1945, there is a symbol near the stem set screw of some Bulova watches. (Check the first link under References for a complete chart.) The 1924 models, for example, have an asterisk next to the screw. If your watch was made in 1946 or later, there is a code on the back or the movements that tells you the precise year of manufacture. For the 1940s, starting in 1946, the code is the last two digits of the year -- hence 46. In the 1950s, the code consisted of the letter "L" followed by the last digit of the year. So 1951 would be L1. With each decade, the code advanced by one letter, so the 1960s started with "M," the 1970s started with "N" and the 1980's started with "P." The progression continues into the 2010s.
Check out the decorative touches on the watch. The swirls of the Art Nouveau style and the austere touches of Art Deco appear on many Bulova watches, particularly those made before the 1960s.
Take the watch to a reputable jeweler, who can examine it for you inside and out. You can also call 1-800-A-BULOVA to talk to a company representative. If your watch has a serial number, the representative can check for you, and if the watch is too old to have a serial number, the representative can guide you to a jeweler in your area who would be able to verify the watch's authenticity.
An authentic Bulova is likely going to be heavier than a knockoff because the works and exterior materials are heavier among the real things.