Very loud noise heard but no collision. What was it?

[Rakuflames]

Originally Posted by Panos

Hello, while living in the boat, in a marina a heard a very loud noise like somebody rammed the boat. I rushed outside but I could see nothing moving around. In a few moments I heard voices from other liveaboards who also heard the same bang. Somebody suggested that there was an earthquake but no announcement has been issued till now. Any idea what it could be?

If you looked at your boat upside down, you would see that it is shaped very much like a bell.

A bell (church bell, etc.) is shaped that way to magnify sound. Things that sound very loud in your cabin may be barely audible -- or not audible at all -- outside of it.

This is why, for instance, when in warm waters, we can actually hear shrimp eating algae on the sides of our boats.

[Rakuflames]

Originally Posted by Hud3

There was a small earthquake near Bucharest last night. It wasn't very big, but who knows what kind of noises it might have made.

This website lists them all and allows you to search by geographical area and time range.

Earthquakes today | Earthquake today | earthquake | earthquakes

Here's the data on last night's event:

Magnitude ML 2.5
Region ROMANIA
Date time 2013-08-27 19:50:44.2 UTC
Location 45.78 N ; 26.75 E
Depth 78 km
Distances 158 km N of Bucharest, Romania / pop: 1,877,155 / local time: 22:50:44.2 2013-08-27
34 km W of Focşani, Romania / pop: 105,112 / local time: 22:50:44.2 2013-08-27
2 km E of Paltin, Romania / pop: 3,687 / local time: 22:50:44.2 2013-08-27

I was in a minor earthquake, in southern Illinois of all places, in 1968 or '69. We heard a loud bang as the earth moved, before the motion waves even got to us. There was a Norge factory about 10 miles away in Herron, IL, and for a second (before the ground started shaking) we thought maybe there had been an explosion there.

The hull of your boat would magnify that sound, and if you were in your cabin at the time, I can imagine that the noise would be both startling and concerning.