Former hurricane Epsilon combined with a low pressure system off Greenland and has been churning up waves of gigantic size in Portugal. People have swarmed to Nazaré, home of the biggest waves ever surfed, as it is directly in the firing line of the swell. According to surf forecasters, who have looked back at 40-plus years of data, a swell of this magnitude happens roughly every two and a half years and this could be one of the largest October swells on record.