Oarweed looks like long broad glossy ribbons. It can grow up to 2 meters in length and down to depths of 20 meters as long as the water is relatively clear and the bottom is rocky. The fronds split into finger-like extensions. This brown seaweed is leathery and flexible. Oarweed has clinging-roots with which it attaches itself under water to stones. It makes a good place for many marine animals and even other seaweeds to live or grown on. Oarweed is edible. You find it sold in stores as kelp.