Wanderlust World Wanderlust World The most common reason a lifeguard orders everyone out of the ocean is rip currents—powerful, narrow channels of water flowing rapidly away from shore. They can form suddenly, move faster than an Olympic swimmer, and pull even strong swimmers into deep water. Panic and exhaustion lead to drowning. Other reasons include lightning, shark sightings, hazardous surf, pollution, or marine life (jellyfish blooms). Always heed lifeguard warnings immediately.