Never underestimate the usefulness of a tarpaulin. Whether canvas or synthetic, a tarpaulin provides cover against the wet both on the ground and from the sky. Featuring eyelets in each corner, it is an immensely practical tool.
You can use a tarpaulin as a groundsheet when camping, or to cover a boat or motorbike at home. Strong and lightweight, they fold up for storage or transport, so you can take them anywhere. Tie down all four corners.