True ... but there are thousands of us that sail (sailed) small yachts which have a more limited range if they have radar at all (power consumption and antenna height cause certain restrictions). AIS on the other hand works great and also integrates with chart plotters for collision alarm with relatively small amounts of power. Small yacht sailors generally assume that cargo vessels will NOT try to avoid them, so having the ship continue on its (drifting) course wouldn't be too surprising.