This is derived from "River Life of the Empire" pages 6-8, from the Death on the Reik WFRP 1e adventure supplement

Choose either 0 for "Day" or 1 "Night" for the timing of the encounter

Then Choose either 0 for "Populated" or 1 for "Remote"

Does an encounter occur?

Is there a Hazard or Special Encounter?

What type of encounter?

As the adventurers' vessel passes his/her boat, a Fisherman catches an aquatic monster of some description; perhaps a giant fish, or a Fen Worm (WFRP, p237) or a Bog Octopus (WFRP, p233), which has moved into the river for some unknown reason...

The Gypsies warn the adventurers of a mysterious whirlpool or terrible monster ahead, and offer to sell them a them a charm which will keep them safe from it...

The adventurers encounter an apparently deserted boat (see Loose Boat below), drifting down the river. As their boat draws level with it, its pirate crew springs into view; some grappling hooks are thrown at the adventurers' boat, and the remaining pirates keep up a withering fire of arrows and crossbow bolts as the two boats are pulled together...

The adventurers encounter a showboat, a couple of hours out from the last town it visited. It has been stopped and is being searched by the River Patrol, who are searching for a child missing from the town - Hanna Hochburger, the daughter of the town's mayor...

The adventurers encounter what appears to be a normal trading boat, whose crew will be happy to spend some time talking about river conditions and general gossip. A River Patrol vessel appears in the distance, and the "trader" takes off at high speed...

For the most part encounters with trading boats will be uneventful, offering the adventurers a chance to pick up local gossip and information on river conditions and the like...