[smurphny]

It seems like a good idea to leave the boat in the Bahamas but a glance at the land elevations make it obvious that the 15-20' storm surge of a major hurricane would inundate almost everything in its path. The same can be said about much of Southern Florida as well.

 

[smurphny]

When is the last time the Bahamas got a 15 to 20 storm surge? I went through Katrina, and I laughed when they told me in the Bahamas they had some bad hurricanes, standing next to buildings that were obviously 40 to 50 years old and only five feet or so above seal level.

I've seen what a 15 to 20 storm surge does, and it doesn't leave anything like that still standing in its path.

I think the geography of the Bahamas prevents them from getting bad surges. But, I imagine a rage sea at the cuts during a hurricane would have to be seen to be believed though.

A 15' storm surge would be predictable even for a class 3 storm in the Bahamas. Here's a NOAA model: http://www.wunderground.com/hurricane/surge/bahamas_mom3h.png

For a class 5 storm, I was surprised at how high the surge could be. Scary. I would not want to be anywhere in the Bahamas for a big one.

This Wikipedia piece notes a 25' surge during hurricane Andrew:

 

[smurphny]

I am somewhat surprised at that report of a 25' surge in the bahamas because most of the bahamas dont have the sort of geography that would cause such a surge. In most cases, the water surge simply goes around the island. In the Abacos, there are buildings a century old at waters edge.
My own boat has been in the Marsh harbor boat yard during two hurricanes with the eye passing directly overhead and I had only a bent stanchion. Boats that came into the yard too late to get put on good stands were damaged by a small surge. I watched the webcam at Mangos Marina (where I keep my boat in Winter) during one hurricane and saw that almost all boats had been moved "somewhere" and the docks were submerged.
My insurer requires me to have my boat out of the water during hurricane season. There are only two yards in the Abacos, one on Green Turtle and the one in Marsh Harbor. The one in Marsh harbor is too small to handle everything before a storm and I dont know how big the one on Green Turtle is.
I've been told that some people have moved boats up to Green Turtle to Black Sound and up into the mangroves to survive a storm. The Harbor at Hope Town seems well protected and I might consider a mooring far up in one of the creeks there.
On Grand Bahama, I might think of moving a boat up the Lucayan Waterway where there are numerous finger canals devoid of anything, anchor at the end with lines to the sides. There are two yards on Grand Bahama, one 10 miles west of Lucaya is not well protected. The further west one is better protected.

I've looked at the land elevations in the Bahamas trying to find places that look like they might be more safe during a storm but it all depends on the wind direction which may be impossible to predict. The mangrove idea is good unless the area becomes exposed from a surge, allowing the ocean waves to get in. I think the best decision is to head back to the mainland DAYS ahead of a potential hurricane.

Those SLOSH graphics surprised me too.