If you've ever stepped foot in the ocean or walked the beach after a storm or at low tide, you have already been introduced to seaweed. Strewn and tangled on the shoreline or drying and decaying in the sun, it does not make a lasting first impression. However, seen growing underwater in its natural environment, waving gracefully from side to side with the movements of the currents, it is a majestic sight that's hard to forget.