What type of ships show up on an AIS display?
Just about every commercial vessel will have an AIS transponder. Specifically, AIS is mandatory on all ships of 300 gross tonnage and upwards engaged on international voyages, cargo ships of 500 gross tonnage and upwards not engaged on international voyages and passenger ships irrespective of size. See the US Coast Guard web page on AIS for more information. Other smaller commercial ships, such as fishing vessels, will equip themselves with AIS transponders voluntarily since there are major safety benefits to using AIS.
