[3.5e] River encounters

[Kaeso]

I'm running a campaign for a friend (my 3rd campaign ever, so I'm still a bit of a newbie) and to make a long story short, his character is a Dwarf Warblade that wants to join an order of famous knights, and thus he will be sent across the land for some errands to prove his worth. I'll make an NPC companion to back him up during all of this. This NPC will also take care of healing etc.

The "problem" is that I've made a map of the Duchy where the orders chapterhouses are located, and it has quite a lot of rivers. I'm afraid that my friend will come with the idea to travel across the river with a ferry boat (or any other boat with a captain willing to earn some gold) instead of overland. It would be unreasonable to refuse such a plan (since it makes a lot of sense), but that would mean that there wouldn't be any random encounters. Does any of you have any ideas for encounters that can take place during a travel over a river?

[Keld Denar]

Chuuls are riverdwellers, and quite nasty indeed.

Otherwise, aggressive plants like Assassin Vines might live on the apex of a river bend to pluck unsuspecting commoners and PCs from their rafts and barges.

Giant Crocs might be another valid threat. Don't forget, D&D Crocs are like, 20+ feet long.

[hamishspence]

Giant constrictors, as anacondas or reticulated pythons, might also be appropriate.

[Cyrion]

If the rivers are a major travel artery, you'll have many of the same opportunities for encounters on the river as off- wanderers, gypsies, bandits, raiders, etc. You just have to come up with an excuse for interaction- the river's narrow at this point, someone needs help or pretends to need help...

Rivers are also a favorite haunt of all kinds of critters, both natural and unnatural. If you're somewhere isolated, the fey could be a great source- nymphs, naiads, kelpies, etc.

Also recognize that for an airborn predator (giant eagle, dragon, wyvern, peryton, etc.) a boat on the water may be great pickings- crunchy on the outside, chewy on the inside with little opportunity for escape because boats are slow and have difficulty hiding.