Police say the man then grabbed both watches and took off.
The suspect is described as a white male, between the ages of 18 and 25, 5 foot 7 inches to 5 foot 11 inches, about 150 to 180 pounds, with brown hair and a military-style haircut. He was wearing a yellow Polo shirt with stripes, dark jeans and dark shoes.
A $1,000 reward is being offered for information that leads to an arrest.
Anyone with information is urged to call Ventura County Crime Stoppers at (800) 222-TIPS.