What to do???

[b.a.s.17]

My wifes uncle offered me $1,000 to rent my boat for 2 days and he's wants to take it down the Arkansas River from Little Rock to the Mississippi River. He is trying to travel the Arkansas River from Tulsa to the Mississippi. He has split it up into 3 different trips, and this is the last part of his trip. What do you guys think? Anyone familiar with the river in that area is it deep or does he need to know his way around? I don't know how far it is but my first thought was I don't know if you'll have enough gas to make it. I'm thinking no just because if something happens to the motor I don't want to create and awkward situation cause I wouldn't wanna pay for the repair...