Dimensions: The dimensions below are based on using size #10 crochet cotton and a size #8 steel crochet hook. Jellyfish: 5 1/2 inches by 9 inches (length measured to end of longest tentacle). Seahorse: About 5 inches long. Seaweed: The center blade is about 18 inches. After each piece is worked, they are then arranged on a background and attached by using spray adhesive.