Recently during Hurricane Isaac, I prepped my boat by making the dock-lines as lose as possible and still stay within the confines of the slip. I went a few days before and added a couple of lines - especially to boat next to me that was secured with what looked like frayed shoe laces. I watched a tidal gauge update hourly on the water level in my marina. It went over 7 feet above normal. I went to check on it afterwards and ran into the marina staff. They had told me that they were out during the storm adjusting dock lines. I had almost no damage.
From what I've seen over the years, the weather service will give worst-case predictions on things like storm surge and you are probably not going to see 11 feet, but, as in the case with Isaac, they didn't predict the storm stalling and pushing more water into the lake here. The best thing is to hope the forward speed of the storm is high so it will be through the area before significant water can be push in prior to the surge. Good Luck.
