Apparently sea sickness is not the only illness you can get on board cruise ships.

According to a recently released report, dirty restrooms on ocean liners are responsible for numerous outbreaks of gastrointestinal (diarrheal) illness over the past few years, citing that most restrooms on these ships are not being properly cleaned.

Researchers have identified contamination with norovirus as the problem in almost all of these infections, even though, they say, the ships are relatively clean in appearance.

"Norovirus can survive for weeks on surfaces at room temperature, and it is difficult to kill," said one researcher. "It’s a tough virus that isn’t killed by alcohol hand rubs. Chlorine bleach is the only thing that works."