How do you beat the noken on twisted thicket on poptropica?

The creature (the Nokken) turns invisible, but you can see his red footprints or air bubbles in the water. The secret is to hide as you go, because the Nokken will not attack you when you are hidden. Watch for the red footprints to disappear then move quickly. Swim through the first pool, then jump past the sealed door to reach the end pool. Do *not* jump onto the vine as you cross to the pool!