"To be Star world champion I think is the biggest achievement that a sailor can have," Prada said. "To win two times is to be a part of the story of Star class, it means a lot. The Star class is very special. It's the class of all the biggest names.''
The silver medal went to Robert Stanjek and Frithjof Kleen (GER), while Mark Mendelblatt and Brian Fatih (USA) won bronze after an exciting and close Medal race fought out on Centre course.
"It's a big achievement because all my life when I was sailing Laser I was dreaming about sailing the Star and winning the World Championship one time, so managing to do it twice is a really big thing for me," Scheidt said.
"This year we have improved a lot in our sailing and our main goal was always to do well here in Perth, so coming through this year and managing to peak at this moment is very special.
"It means that we are on the right track for the 2012 Olympics."
Meanwhile in the Women's 470, 49er, Men's RS:X and Laser the top ten places for the Medal Races were decided as fleet racing drew to a close.
Fluky winds played havoc with the Laser Gold fleet's final two races with two rank outsiders in the USA's Rob Crane and Croatian Milan Vujasinovic claiming victories.
But Tom Slingsby (AUS), who had a rocky day by his standards, remains 14 points clear of Germany's Simon Goteluschen, who came in under the radar with a second and a dropped 23rd.
With a seventh-place finish ensuring him of victory if Groteluschen wins on Sunday, Slingsby is on target for his third Laser world title and his ultimate goal of gold at next year's London Olympic Games.
World #1 pair Nathan Outteridge and Iain Jensen (AUS) are one step closer to winning the gold medal in the 49er after finishing Saturday's three Gold fleet races with an impressive 17 point overall lead. As the rest of the fleet battled for a Medal Race position, Outteridge and Jensen placed fifth, seventh and tenth to bring their points tally to 85.
Despite holding first place throughout the week, John Pink and Rick Peacock (GBR) had a disappointing day, placing 24th in Race 13 and 23rd in Race 15. This result means the British have dropped from the lead to third with 106 points, bumping Emil and Simon Toft Nielsen (DEN) into second place with 102 points.
Outteridge and Jensen are guaranteed a medal in Sunday's final but must beat the Toft Nielsen brothers in order to secure the World Championship.
Spain's Tara Pacheco and Berta Betanzos look certain to finish on the Women's 470 podium as they lead the fleet on 49 points. Pacheco and Betanzos's closest competition going into the Medal Race is the Israeli duo of Gil Cohen and Vered Buskila, sitting 11 points behind on 60.
With only 10 points separating second and sixth places, competition for the remaining spots on the podium will be high.
Despite a disappointing start to the regatta Australia's Elise Rechichi and Belinda Stowell earned a spot in the top 10, finishing third in Race 9 and fifth in Race 10 to qualify for London 2012.
There was fast wind and equally fast windsurfing in the Men's RS:X Gold fleet racing with Piotr Myszka (POL), Dorian van Rijsselberge (NED) and Przemyslaw Miarczynski (POL) filling the top three places overall.
Just one point separates World #1 Myszka and van Rijsselberge ahead of Sunday's Medal Race.
Live Streaming from the final day of sailing at Perth 2011 will be available from 12:45 - 18:00 local time (05:45 - 10:00 GMT). The live stream is available here.
The Perth 2011 ISAF Sailing World Championships website will bring you results, tracking, live updates and all the latest news both on and off the water.