The final entry numbers are 155 sailors from 26 countries in 80 boats doing battle in the three Paralympic classes; 2.4mR one-person keelboat, SKUD two-person keelboat and Sonar three-person keelboat.
On opening the event, Merkle said: "I can't tell you how pleased I am to see so many old friends, so many new friends and so many countries represented here, this is a true thrill."
The 2011 IFDS Worlds are also the final qualification regatta for the 2012 Paralympic Sailing Competition.
Last year's Worlds in the Netherlands provided the first opportunity, which means seven countries in the 2.4mR and Sonar classes and six in the SKUD, plus Britain, which is automatically allocated a slot per event as the host nation, come into these Championships with the pressure off. However for everyone else, qualifying their country for London 2012 is objective number one this week.
Based on the maximum number of boats per class allocated for London 2012 (14 x 2.4mR, 12 x SKUD and 14 x Sonar) there are still six slots available to be filled in the 2.4mR and Sonar classes, and five in the SKUD. After the final qualified nation lists have been confirmed, countries will then begin selecting sailors for London 2012.
A bronze for reigning Beijing 2008 Paralympic Sonar champions Jens Kroker, Robert Prem and Siegmund Mainka at last year's Worlds guaranteed Germany will have a boat in the three-person keelboat event in 2012.
Helm Kroker is keen to use this event to assess his team's progress against their likely 2012 rivals. He said: "The main thing for us is to be together as a team and practice together because I'm living in Brazil and my team is living in Germany so we really have very little time to spend together. I learned at Sail for Gold our competitors are really practicing a lot; some of them are sitting on the boat each and every day and we only spend 30-40 days per year in the boat but I like the challenge. We have 10 teams in the fleet who are very good and each of them can really win here. I expect the British team (Robertson/Stodel/Thomas) will be in the top three, the Dutch team (defending Worlds champions Hessels/Van Der Veen/Rossen) is very, very strong and there are a few other teams who are really on a par."
The RYA's Tim Hall, event director, added: "Most people have basically stayed around since Skandia Sail for Gold last month so the venue has been really buzzing as everyone has started gearing up for the start more and more as the week has gone on. The atmosphere has been reasonably relaxed with loads of space for trailer parking around the boat park and plenty of space on the pontoons, which all really makes a big difference in running a Paralympic classes event. The Academy has been really accommodating and now everyone's really looking forward to getting down to the serious business of racing."
The IFDS Disabled Sailing Combined World Championships 2011 are being organised, and run, by the RYA, supported by UK Sport.
For all the latest news, results and reaction from the IFDS Disabled Sailing Combined World Championships 2011, including our exclusive daily vodcast, visit www.ifdsworlds2011.com