There's a pair of oars somewhere on Monkey Island.
And they're way below sea level.
Look at the crack just north of the south shore.
Now, how can you get to the oars at the bottom of the chasm?
You need to know the ropes...
Or at least have them.
You'll need two pieces of rope.
First Piece (Easy)
Second Piece (Hard)
You have to tie the ropes to something, and you can't tie them together.
Look at the crack for things to tie the ropes to.
Look for sturdy things.
Sturdy things that are firmly rooted.
The tree and the sturdy stump will do.
Tie one rope to the tree to climb down a little.
Tie the next rope to the stump to reach the base of the crevice.
You can now retrieve the oars.