To help readers cope with the elements, we offer the third in a series of summer survival guides.
Life in Florida has its share of spectacular perils _ lightning, tornadoes and hurricanes.
But one of its deadliest natural features is invisible and silent.
Riptides, powerful currents created by water rushing through gaps in sandbars just off the beach, killed 22 people last year in Florida.
In comparison, lightning killed eight in 1994, a record that goes back to 1959.
Riptides are perennially the leading cause of weather-related deaths. They kill 20 to 25 people a year.
Atlantic riptides killed five swimmers in one day in May 1994.
Riptides can be fiercely strong, making it difficult for even good swimmers.
They are most likely to occur after storms. Milder seas mean stronger sandbars and less likelihood of a break, but they can develop even in calm seas.
They flow away from the shore and can occur anywhere with long, sloping beaches.
They can be 30 feet wide and 150 feet long.
The currents pull swimmers out to sea as if they were caught in a river.
On the Gulf Coast, they are common near inlets and piers. In Pinellas County, the worst areas are near the north beach at Fort De Soto, John's Pass and Clearwater Pass, officials say.
_ Information from Times files was used in this report.
When water swept inshore by surf is trapped behind a submerged obstacle, such as a sandbar, it may return seaward in a powerful flow known as a rip current, or rip tide. Rip currents are found off many long, gently sloping beaches.
If caught in a rip current carrying you out to sea, remain calm. Swim parallel to the beach. The rip current is narrow and you should clear it in a short while. Do not attempt to swim back to shore against the rip current. The effort could exhaust and kill even a strong swimmer.
Sources: NOAA, Time Life Books