How can I use the circles?

Hint 1 of 8:

You must find them in the bow of the ship.

Hint 2 of 8:

Then, click on them to active them.

Hint 3 of 8:

You are looking for something to guide the ship.

Hint 4 of 8:

The two buttons can slide in their tracks.

Hint 5 of 8:

Slide the left button to the top.