Usually I'll do the same thing on long stretches of coastline if no cities are using the tiles. In addition to the aerial defenders, you can put blimps in them to do recon and spot approaching enemy naval fleets in time to do something about them, BEFORE they can sneak-attack one of your coastal cities.
An automatically repeating recon mission would be nice to have, wouldn't it?
Lastly, I almost ALWAYS put a fort on any oil supply I find right as soon as Sci.Method is researched.
I confess I spurn this as too blatant a prior-knowledge attack.