The Amazing Race: Unfinished Business

 is the eighteenth installment of The Amazing Race. It was confirmed on Nov. 5th, 2010 and is the first US season of The Amazing Race broadcast in High-Definition Format.

This is an All-Star season comprising two teams from Season 12, five teams from Season 14, two teams from Season 15, one team from Season 16 and one team from Season 17.

Teams

 * Main article: The Amazing Race 18 Teams

Results
The following teams participated in the Race, with their relationships at the time of filming. Placements are listed in finishing order:


 * All contestants appeared on more than one season.

Leg 1 - Episode 1
Title: "Head Down and Hold On" –- non-contestant
 * Starting Line: San Gorgonio Pass Wind Farm, Palm Springs, California
 * Teams had to search a field of paper airplanes to find one with "Qantas" written on it using the clue: "Queensland and Northern Territory Aerial Services", then return the airplane to Phil in exchange for their tickets to Sydney
 * The first 8 teams would be on the 1st flight, the rest on a 2nd flight, with the last team receiving an automatic U-Turn after completing this leg's Detour
 * Flight from Los Angeles International Airport, Los Angeles, California to Sydney (Kingsford Smith) Airport, Sydney, New South Wales, Australia
 * Circular Quay/Sidney Ferries to Manly Wharf, Manly
 * Oceanworld Manly
 * Swim With Sharks: One team member must scuba dive and search for a compass hidden on the floor of a large shark tank, then use the compass to decipher a series of nautical flags which tell them the next location and catchphrase which they must tell the Commodore ("I am between the Devil and the deep blue sea")
 * Manly 16ft Skiff Sailing Club
 * Sail 16 Foot Skiff: Join a skiff crew and sail along a course to retrieve the next clue
 * Shelly Beach, Manly(leg midpoint)

Leg 1 - Episode 2
Title: "I Never Looked So Foolish in My Whole Entire Life" –-tba

Memorable Moments

 * The teams who were expected to land in Australia first got delayed due to a medical emergency of a sick passenger.

Franchise

 * First season to have an automatic U-Turn.
 * First season to have the first leg as a double-length leg.
 * No one is sent to the Elimination Station after the Episode 1.
 * First season to have Episode 1 end with a cliffhanger.
 * Most parent/child teams in a single season, 4.
 * Lowest number of couples in love, two.