Abstract: An anchor for boats comprises a hollow body having an outer shell of molded resinous plastic material. The body includes an integral stem having a lower end integrally joined to a ballast chamber elongated to extend transversely of the stem in opposite directions. A pair of claws are integrally formed to project transversely outwardly of the ballast chamber and transversely of the stem axis for engagement with a supporting bottom surface under water. The outer shell is designed to withstand loads imposed by an anchor line between the stem and a bottom engaging fluke or claw. Ballast material such as metal punchings and scrap pieces, and/or concrete is carried in the shell to provide sufficient anchor weight for causing the flukes or claws to bite to dig into the underwater bottom surface and hold.