Vessels over 300 gross tonnes must carry automatic identification system (AIS) transmitters, but the two AIS receivers in the Aleutians only cover about 10% of the islands.

• 尽管毛重超过300吨的船只必须携带自动识别系统（AIS）发射器，但阿留申群岛上仅有的两个接受器只能覆盖岛屿的10%25。