Iglesias, known by his nickname Dorado, was the World Professional Marathon Swimming Federation world champion in 1967, 1969, 1971 and 1972. He was runner-up in 1968 and 1970. He won the 24 Heures La Tuque relay swim six times with three different partners, including Egypt’s Abou Heif and Holland’s Judith DeNys. He also won the 34 km (21-mile) Traversée internationale du Lac St-Jean professional race in Canada in 8 hours 55 minutes in 1967, in 9 hours 31 minutes in 1968, in 9 hours 32 minutes in 1969, in 8 hours 39 minutes in 1971 with a second in 1970, and excelled in the warm-water professional marathon swims in South America including the Maratón Acuática Internacional Santa Fe - Coronda in 1965, 1967 and 1970. He won the 37 km (23-mile) la Descente ou remontée du Saguenay in 6 hours 3 minutes in 1967 and was fifth in 9 hours 22 minutes in 1968.
- Round And Round They Swam 24 Hours In 15°C
- International Marathon Swimming Hall of Fame website
- Open Water Swimming website
- Marathon Swimming
- What Goes Around Comes Around
- World Professional Marathon Swimming Federation
- Who Will Top Maratón Acuática Santa Fe - Coronda in 2014?
- The Turbulent Traversée, Jan Van Scheijndel In Lac St-Jean
- Sharp As A Swimmer, The Mervyn Marathon Magic