World champion pro surfer Kelly Slater may have to “hang 10” in a California courtroom over a trademark dispute involving him and surfwear company Quiksilver. Rival New York apparel maker World Marketing alleges Slater’s brand, VSTR, which launched in January, violates a trademark it had for its Visitor apparel line. Quiksilver has claimed VSTR was based on the initials for “visiting, surfing, traveling and responsibility,” and Slater has said in interviews the name was inspired by the word “visitor.” World Marketing has owned a “Visitor” trademark since 1998, and in March the company sent Quiksilver a cease-and-desist letter. Quiksilver, in turn, filed a complaint in a Santa Ana, Calif., court saying it didn’t infringe on the trademark. World Marketing has countersued. Though Slater isn’t named in the original complaint, World Marketing served a subpoena to him on Nov. 14 to get him to testify. Slater responded by saying he was too busy “preparing full-time” for the Association of Surfing Professionals World Championship Tour and couldn’t appear until January. World Marketing Vice President Neil Mossberg told us: “I can’t really talk about the case. However, I will say this: I know we are not as famous as Kelly Slater, and I know our stock is not traded like Quiksilver’s. However, I also know we will not be wiped out without a fight.” Lawyers for Slater and Quiksilver didn’t get back to us.