With five drownings so far this season, the number of New Jersey's rip current-related deaths is already above average.

The combination of a mild winter and the lure of the ocean on hot summer nights have created the fast-moving water channels and tempted some beach-goers to swim on beaches without lifeguards.

Jon Miller, a professor at Stevens Institute of Technology in Hoboken, told the Press of Atlantic City he and his students have developed an app that lets lifeguards share information about rip currents for the National Weather Service to use in its research.

Rip currents typically look like channels of choppy water and appear as a difference in color or a line of moving foam or debris.