Shamrock I was a racing yacht designed by Sir Thomas Lipton in 1899. It was the first of a series of yachts built to compete for the America's Cup, a prestigious sailing competition. The yacht was constructed in Scotland and featured a sleek design aimed at maximizing speed and performance on the water. The vessel was notable for its innovative use of materials and design techniques for its time. Although Shamrock I did not win the America's Cup, it laid the groundwork for future designs and contributed to the evolution of competitive sailing.