Airdate : October 16 , 2011 This Leg 's Detour was a choice between Coral Reconstruction and Beach Preparation , tasks designed to give back to Thailand following the 2004 tsunami . In each task , teams rode on speedboats to Khai Nai Island . In Coral Reconstruction , teams built a coral nursery out of pipes . Once complete , they used a kayak to take the nursery and several coral fragments out to a buoy where they had to set the nursery on the ocean floor , then set the coral fragments into the nursery . Once complete , a marine biologist gave them their next clue . In Beach Preparation , teams had to set up a series of twenty beach chairs and ten umbrellas marked with a specific symbol given in their clue . Once the chairs and umbrellas were set up to the beach club owner 's satisfaction they received their next clue
2004 tsunami
2004 Indian Ocean earthquake and tsunami
The Amazing Race 19