Even the Big Sur coastline of California has its moments of imperfection. But they’re mostly man-made.
And since vacation is no time to let down your grammar/usage guard, I endangered myself and others in order to snap this photo and pass along an invaluable lesson.
Insure should be reserved for insurance matters. Like if you hit a bicyclist you say, “Don’t worry about the scratch on my bumper, the car’s insured.” In most other cases, like the one in the photo, “ensure” is the proper choice.
Though if you really want to get picky, ensure is not such an ideal word either. Would the act of not entering that area really ensure the public’s safety? What if you’re standing back at the recommended distance and are struck by lightening or mowed down by an avalanche?
Ensure implies a kind of guarantee that few lawyers would allow you to claim if you’re talking about safety or products or services.
So instead of ensure, try assure. In some cases, enable might also be a good substitute.
But never insure. Almost never.