Open Water Swimming Career
- Marais participated in the 2009 FINA World Championships in Rome, Italy.
- Marais participated in the 2011 FINA World Championships in Shanghai, China where he swam the 5 km race.
- Marais completed the Round The Rocks Swim at Blouberg on 8 May 2011. Marais was part of Team Young Money that won the Relay Race with a prize of $5000.
- Marais is a formidable cold water swimmer and is a former winner of the Youth Day Swim, when the course was from Clifton to Camps Bay.
- Marais won the 2.5 km Cadiz Human Rights Day Swim at Camps Bay (on 21 March 2010 and 2012).
- Marais won the 2014 Metsi Open Water Swim 10 km marathon swim in Jeffreys Bay.
- Marais finished third in the 2015 Midmar Mile.
- Marais won the 2015 Sanlam Cape Mile in South Africa.
- Marais finished 22nd in the 5 km race at the 2017 FINA World Swimming Championships in Lake Balaton, Hungary on 15 July.
- He competed on the 2019 FINA / CNSG Marathon Swim World Series in Seychelles on 12 May 2019.
- He won the Greendale Superspar Capital K Open Water Swim on 22 November 2020.
- Danie Marais, Sasha-Lee Corris Win Greendale Superspar Capital K Open Water Swim
- Danie Marais, Michelle Weber Win 10K Metsi Open Water Swim
- Ho High Fives At aQuellé Midmar Mile
- Relay Results At The 2015 aQuellé Midmar Mile
- aQuellé Midmar Mile
- World Open Water Swimming Series
- Chad Ho Enjoys Six Pack At aQuellé Midmar Mile
- Winning From Above At aQuellé Midmar Mile
- Ho No, Here Comes Marais
- Split Times Taken At FINA World Championships
- Marc-Antoine Olivier Makes A Fast Statement In 5K