Because of the dense populations along coasts, storm surge is the greatest potential threat to life and property associated with hurricanes. Storm surge is a large dome of water from 50 to 100 miles wide that sweeps across the coastline near where a hurricane makes landfall. Caused mainly by the high winds pushing the ocean surface ahead of the storm, it can be 15 feet deep or more at its peak. During Hurricane Ivan, Grand Cayman experienced an 8-10 foot or higher storm surge that affected most of the island, including large areas of George Town.
The level of surge in a particular area is determined by the intensity of the storm and the slope of the continental shelf. A shallow slope off the coast will allow a greater surge to inundate coastal communities. Communities with a steeper continental shelf will not see as much surge inundation, although large breaking waves can still present major problems.
The steep drop-off beyond our reefs ('the Wall') means that Cayman is surrounded by very deep ocean. We tend not to experience storm surges with smaller storms.
However, surges do develop in the North Sound because of its shallowness, making areas bordering the Sound (including Cayman Kai, Rum Point, Tropical Gardens, Red Bay, Prospect, George Town Barcadere and areas bordering or near to the North Sound) vulnerable to surge flooding. This was the key factor in the devastating impact that Hurricane Ivan had on the Cayman Islands in 2004.
Storm tides, waves, and currents in confined harbors severely damage ships, marinas, and pleasure boats.