Olympic athletes competing in the waters off Rio’s shore dodge human feces, the invisible rotavirus, and dead bodies in pursuit of gold.

This game ranks not as an official Olympic sport but as a necessity for athletes competing on the open waters during the August event in Rio.

“We just have to keep our mouths closed when the water sprays up,” Afrodite Zegers, a sailor on the Olympic team of the Netherlands, reasons to the New York Times.

Rather than a 17-day infomercial for Brazilian tourism, the games risk alienating wealthy foreigners from traveling to the former Portuguese colony. The polluted waters, which pose more of a risk to tourists watching the Olympics than to athletes participating in it, join Zika, unchecked crime, terrorism, and other worries as threats to the success of the Rio games. Even the local cuisine may leave a bad taste in tourists’ mouths.

“When you open up the fish, their innards are black with oil and muck,” a fisherman tells the Times. “But we clean them with soap and eat them anyway.”

While swimmers and divers compete in chlorinated pools, other athletes compete on if not in the open waters. Sailing and canoeing both take place atop the sea with dangers levels of bacteria because of dumping and raw sewage pumped into the salt water.

“Foreign athletes will literally be swimming in human crap, and they risk getting sick from all those microorganisms,” Brazilian pediatrician Dr. Daniel Becker explained to the Old Gray Lady. “It’s sad, but also worrisome.”