DEL MAR, Calif. -- Big crowds will gather Wednesday "Where The Turf Meets The Surf" to mark the start of the Del Mar Thoroughbred Club's 68th horse racing season with the traditional opening-day festivities.

Prizes will be awarded to those who wear hats judged to be the most glamorous, outrageous or have the best flowers or racing theme during the One and Only Truly Fabulous Hats Contest.

The racing schedule on opening day also includes the $100,000 Oceanside Stakes, a mile-long turf race for 3-year-olds.

New this year is the $9 million Polytrack racing surface, which is a mixture of sand, fibers, rubber and wax, which track officials have touted as safer material for both horses and jockeys.

The track, however, does not contain an ingredient called "jelly cable," a waste product imported from China made up of chopped-up, lubricant-coated plastic previously used to insulate stripped copper wire, the Los Angeles Times reported.

The substance was used in Polytrack turf installed at Chicago's Arlington Park and at Keeneland Race Course in Kentucky, where officials call the racing surface "outstanding," according to The Times.

But at Del Mar, concerns about copper contaminants fouling the shoreline arose after tests detected "higher levels of copper" in track water runoff, the newspaper reported.

Bing Crosby coined the term "Where The Turf Meets The Surf" in a 1941 song that pays tribute to horse racing in Del Mar. It has since become the theme for the 43-day racing season.

Crosby and fellow entertainer and film actor Pat O'Brien founded the Del Mar Thoroughbred Club in 1937.

Races are held every day, except Tuesdays, through Sept. 5 at the Del Mar Fairgrounds, 2260 Jimmy Durante Blvd. First post is at 2 p.m., except on Fridays, when races start at 4 p.m.

Highlights of the season include the $1 million Pacific Classic on Aug. 19. Four O'Clock Fridays will include performances by Unwritten Law, Satellite Party, Violent Femmes, Pinback, Cake, Pete Yorn, Angels and Airwaves, The Cult, Ziggy Marley and Super Diamond.