Commercial satellites are ok for seeing planes for that matter. It's knowing where and when to look that's important. I don't think that even the US military constantly monitors vast tracts of empty ocean on the off chance that a plane might crash there.

https://maps.google.com/maps?q=35%C2%B003%E2%80%B234%E2%80%B...

For instance, these two maps are pretty similar in scale (I couldn't make Maps do the exact same scale though)

https://maps.google.com/?ll=44.527843,13.227539&spn=14.14170...

https://maps.google.com/?ll=-32.509762,80.991211&spn=16.6984...

That's a "whole lot of nothin'".