Sounds like helicopters or something buzzing around for the past half hour or more. I am half a mile north of 30A off of 393. My house is vibrating?!?! Anyone else???
We heard the helicopters/noise too (we live off Bay Drive). Called SWSO and they said it wasn't their helicopter. We would also like to know what was going on.
I watched a plane last night make big circles between the bay and the beach. It's definitely military. When it's travelling north toward the bay, the sound of it is louder, like a humming noise. It went on for hours. Maybe that's what you were hearing.