As a general rule, wait 30 minutes after it stops raining to resume swimming, golfing or other activities. People struck by lightning carry a charge. Lightning victims are safe to touch. Many survive a lightning strike but die because bystanders hesitate to resuscitate them. Lightning doesn't strike low places.
Lightning can strike the ground even at low elevations.
Tall objects provide protection. People have been killed by lightning even when they are surrounded by tall buildings. Take cover inside a nearby vehicle or building, Dewey recommended. Walk, never run. Running can create static electricity that attracts lightning.