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SV_CH whale sightings map 2.png

North Atlantic right whale distribution near ports of Charleston and Savannah. Illustration based on NOAA NARW sighting advisory system and NOAA chart 11009.


As whales migrate they cross southeastern port approaches, entrance channels across shallow water. For mother-calf pair, just north of the calving grounds, there are periods of rest, for times and places to nurse. When ships hit whales, the duration varies...a whale may roll up and over a ship’s bow bulb and be struck by the bow stem. A ship may ride over a whale, forcing it below the surface, dragged along the hull, between the hull and channel bottom. Hull hydrodynamics can pull a whale toward the stern of a ship, into the propeller. Negative pressure sufficient to capture a whale may extend for as much as 60 percent of a ship’s beam. A whale that dives to avoid a ship may find channel depth insufficient for escape. Observed injuries resulting from ship strikes include broken bones, massive blunt trauma and severe propeller cuts. Enforcement of the speed limit is the only way to give these whales a measure of protection from ship strikes in port areas. As NOAA reviews vessel regulations, ship speed at Charleston and Savannah should be examined carefully.


Margin of Safety

Modern ships dramatically outsize and outweigh right whales. Post-Panamax ships are more than 1,000 feet long. Panamax class ships, the smaller of the two ship classes we monitor, displace approximately 190 million pounds, and have a deadweight of an additional approximate 145 million pounds.

Speed is the determinate factor in the likelihood of a ship strike.
Slowing ships down is the only way to provide a margin of safety for right whales crossing port entrances, where rerouting measures are not practical. Ship speed needs to be closely monitored, and the speed rule enforced.

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