The course includes natural rivers like the San Marcos, with rapids and dams. Most boats destroyed on the course are lost in the upper river. The San Marcos River converges with the
Guadalupe River and becomes wider and slower. The main dangers in the middle river are sweepers, downed trees, logjams and dams. Near the end of the course there are lakes and swamps, and it ends with a crossing of the
San Antonio Bay. Other challenges include alligators, sharks,
water moccasin,
fire ants, and
mosquitos. There are 11 checkpoints including the finish line. Their locations are published and they are staffed with officials. Each checkpoint has a cutoff time the racers must meet or be disqualified. The final cutoff time at the finish is 100 hours. The team captain of each team must be present at the checkpoint to sign off the team's time as the team leaves. Checkpoints: •
Staples Dam •
Luling 90 •
Palmetto State Park •
Gonzales Dam •
Hochheim •
Cuero 766 (Cheapside) • Cuero 236 •
Victoria City Park • Swinging Bridge (often referred to as Invista or Dupont) • Calhoun Riverside RV Retreat •
Seadrift ==Records==