Sir David Attenborough unveils the two stunning underwater realms of Saudi Arabia - the flamboyant Red Sea and the contrasting hot muddy Gulf, capturing for the first time the rare event of Palolo worms spawning at night.Sir David Attenborough unveils the two stunning underwater realms of Saudi Arabia - the flamboyant Red Sea and the contrasting hot muddy Gulf, capturing for the first time the rare event of Palolo worms spawning at night.