What would a lightning detector be useful at?
As StrikeAlert Lightning Detector can detect and wan of lightning from 40 miles away I’d say it’s a good tool for the work in open field or people that do jogging every day outside, and why not, for you while swimming in the pool.



It comes in a small form factor, with drop-resistance, easy to carry, and uses an audible alarm to warn you to keep your critical electrical and Information Technology resources safe, so you could shut them down when a lightning is tracked.
The distance is indicated by a LED light on the portable device which blinks when the danger approaches at 20-40 miles, 12-24 miles, 6-12 miles and within 6 miles.

You can wear the StrikeAlert Lightning Detector on your belt and provide it power from 2 AAA batteries for up to 100 hours of operating time.
Not only you can track the strike distance but also storm direction and battery life.
It is available at a price of $69.95.