The remains represented a navigation hazard, and as they had been disturbed and damaged by the dredging operations, preservation in situ was not an option.

A new terrain feature, whirlpools creates an additional navigation hazard.

The rapids, or falls, are created by a series of underwater ledges which roil the water in either direction, causing a significant navigation hazard, despite the depth of water.

There are about 60 lights and buoys to mark it because of its winding nature and navigation hazards.

Distress flares are still used by mariners in emergencies, while lighthouses and navigation lights are used to communicate navigation hazards.