"Any beach with breaking waves is going to have rips," Rob Brander, a coastal geomorphologist and senior lecturer at the Australian university, said as he held one of the green-and-white devices Wednesday. The United States Lifesaving Association, a nonprofit lifeguard group, estimates there are around 100 rip current deaths per year. Scientists at Florida International University place the annual toll at around 150, "and they estimate there's probably a lot more than that," says Deborah Jones, a weather service program analyst and outreach coordinator with the rip current program in Silver Spring, Maryland. "Rivers flow in one direction," said Brander, who's spending a month at the Center for Marine Science at the University of North Carolina-Wilmington. Brander said the scientists used inexpensive, off-the-shelf, GPS units connected to multiple satellites to log locational data. There are probably many factors causing the decline but the NWS believes the overall increase in rip current education and outreach is one reason.