I just left my boat where I found the dock lines on my bow broken. Someone (I found out later was the harbor master) secured the bow with some of the remaining line. The harbor master informed me that a Coast Guard rib went by the marina at a very high rate of speed causing what a witness said was about a 4-5 foot swell causing damage to boats and the docks. My slip is right on the Alameda Oakland estuary which exposed to the shipping lane. I have been in this location for 13 years and have never had anything like this happen before. If your boat is in the Alameda marina I suggest you contact the harbor master as soon as possible. He has contacted the Coasties and has forms and people to contact if your boat has any damage. Even if your in a marina close to Coast Guard (Grand Marina) island I would suggest you check your boat.