I used the Treasure Locator Tool provided by tip.it and I put in my degrees and it shows it's at the Baxtorian Falls, but when I take the raft down and try to swim to where my treasure is I always get washed off. How do I get there?

Try To Get To The Last Spot that you can swim to. Try from there

What you mean? I can only swim to the rocks, and the river washes me off everytime.

use a rope on the rock then a rope on the tree

You dont need to use rope to tree, only to rock and walk near the tree and dig there.