Call of Duty: Black Ops Edit
The Sampan first appears in "The Defector", after jumping into the PBR, the player can see some Sampans.
After playing the following levels, again it appears in "Victor Charlie", in which many VC fighters attack the player. After Mason escapes from his downed Huey, he swims up to a sampan, kills and uses a VC as a human shield in the Sampan. Later, during the stealth portion of the mission, Mason kills a VC guard on a sampan with his SOG Knife.
In "Crash Site", it appears the Sampans are more equipped, with at least one RPG on board. Once in the plane, VC fighters come in Sampans in which the player can destroy with their China Lake.
Sampans make a brief appearance in Multiplayer map Cracked, where many of them are stationed in the docks where the SOG team spawns.