While ships are required to broadcast their location through the AIS radar system, they can disable this. When ships "go dark", they are known as dark vessels and may be performing illicit activities such as illegal fishing. We analyzed public data of 55,368 dark vessels and identified several locations where vessels frequently shut off their AIS transponders. In this repo, there are figures and maps from our analysis. We also analyzed other data, such as the number of hours spent dark.
mean 100.400299 std 371.332763 min 12.000000 25% 15.586875 50% 23.495278 75% 67.812986 max 17215.947500
In general, ships spent around 4 days dark on average. However, this is a very skewed distribution.
After removing outliers based on IQR: count: 47884 mean: 34.08340443107881 std: 29.586341438485736 min: 12.0 25%: 14.974722222222223 50%: 20.29083333333333 75%: 40.90951388888889 max: 146.13916666666665
On average, ships spend about 34 hours hidden from AIS radar when they disappear.
mean 857.755972 std 711.376427 min 12.000000 25% 276.000000 50% 736.000000 75% 1269.000000 max 9499.000000