"Watermark" received many positive reviews from critics and it became an unexpected commercial success, which propelled Enya to worldwide fame. It peaked at number five on the UK Albums Chart, number twenty-five on the "Billboard" 200 in the United States, and reached number one in New Zealand and Switzerland. It was certified quadruple platinum by the British Phonographic Industry (BPI) and the Recording Industry Association of America (RIAA) for shipments of 1.2 million and four million copies across the United Kingdom and the United States, respectively. To promote the album, Enya embarked on a worldwide promotional tour which included interviews, appearances, and live performances. Four singles were released from the album, including the international top-ten hit "Orinoco Flow", which spent three weeks at number one in the United Kingdom. "Watermark" was reissued in 1989, 1991, and 2009; the first two contain "Storms in Africa (Part II)" as a bonus track; the latter was a Japanese release with a second entitled "Morning Glory".