Lat / Long:  41^o 53' 24" N, 87^o 35' 24" W

NOAA Charts:  14905, 14927,14928 & 14926

Description:  The construction and improvement of Chicago Harbor began in 1833.  The harbor includes a 970 acre outer basin protected by exterior breakwaters totaling 12,663 feet in length and a 224 acre inner basin protected by interior breakwaters totaling 6,578 in length. The project also includes a 29 feet deep approach channel, a 28 feet deep maneuvering channel and a 21 feet deep river entrance channel separated by the Chicago Harbor Lock. The lock's chamber is 80 feet wide by 600 feet long and is 22.4 feet deep at its low pool elevation. The lock is operated 24 hours per day, seven days per week.

Navigation Depths:  The above depths are the authorized navigation depths for the project and are referenced to Low Water Datum 1985. The actual navigation depths may vary due to fluctuations in the level of Lake Michigan and the occurrence of shoaling within the navigation channel. This project was last surveyed in July 1992. Copies of this survey can be obtained by contacting the: