NOAA's National Weather Service Weather Forecast Office

Observation Network

One of the most important improvements in marine technology since 1975 is the number of real-time observations that now exist. In 1975, there were no data buoys on the Great Lakes, nor any data from automated stations. The only real-time observations available to the mariner were shore and ship reports. The main method the commercial mariner obtained observations in 1975 was via VHF voice radio. Typically, a mate on a boat would tune in to the Coast Guard frequently to get up to date observations. The mates would then plot these observations on a map for the area of interest, essentially creating their own weather surface chart. The observation system on the Great Lakes began to dramatically improve in 1979 as eight data buoys measuring wind speed and direction, and wave height began to be dispersed in the water. This was a direct response to the Edmund Fitzgerald disaster. Additional weather equipment was also added to some of the Great Lakes lighthouses in 1983. This network of stations which measure wind direction and speeds, air temperature, and surface pressure is known as the Coastal Marine Automated Network (CMAN).

Buoy and C-MAN stations across Lake Superior: