This data set is from a survey comparing the size and shape of limpets in the high intertidal zone compared to the low intertidal zone on a rocky shore in Western Port Bay, Victoria. On 10 sampling occasions from April to October 1987 the length, width, height, distance from apex to the posterior margin, distance from apex to the anterior margin and the number of ridges of 350 limpets were measured in both zones. The tenacities of individual limpets in the 2 zones were collected in September and October 1987. Tenacity was measured with a hand-held device that applied a horizontal force until the limpet was detached from the substrate.