The diving season in Ecuador is year round but you should choose to visit depending on what you want to see. Whale shark season in Ecuador is in the cold period of July to December. The plankton blooms and current bring big fish like whale sharks although the visibility is slightly reduced. The water temperature goes down to around 60-65°F (16-18°C) so a semi-dry is recommended. The wet season in Ecuador brings calmer weather conditions and legions of hammerhead sharks and mantas to the islands. There are significantly less waves at this time of year as well and the water temperature is around 70-80 °F (21-27 °C).