Ich zitiere aus den FAQ zu 4.2.4:
If the War Canoe uses its last movement point to get to the hex, there's a Battle in the hex. (A very short Battle
if it's only a Rumor!) If the War Canoe has another movement point left (or two, or even three, if he's
got the right card or two) then it's the other player's responsibility to reveal if he has a War Canoe in the
hex. If there is one there, then there must be a Battle in the hex. If there's no enemy War Canoe in the
hex, then the moving War Canoe must decide weather to continue moving or battle the Transport Canoe
(or Rumor) that's there. It's your responsibility to reveal the face-down War Canoe if somebody else
wants to move through the hex, i.e. you have to reveal it. You almost always want to stop your
opponent, anyway.