02:45Earth: The Power of the PlanetOceansBBC Two Duration: 59 minutes Audio described Thu 13th Dec 2007, 02:45 on BBC One WalesAvailable for yearsWatch nowGeography series with Dr Iain Stewart. Iain travels to surfers' paradise Hawaii to learn more about oceans, explaining the difference between waves, tides and currents.ContributorsPresenter:Iain StewartGenresFactualScience & NatureFormatsDocumentariesSeriesEarth: The Power of the Planet Source: BBC Online