Ricochet
ric·o·chet [rik-uh-shey, rik-uh-shey or, esp. British, rik-uh-shet]
noun
1. The motion of an object or a projectile in rebounding or deflecting one or more times from the surface over which it is passing or against which it hits a glancing blow.
The idea for this cache came to me while I was driving by the gz on my way to a doctor's appointment... And I rather enjoyed the idea! The question is... will you?
All the stages except the final are magnetic, the hint gives further details. No need to open the tubes, they are see-through in order to keep them waterproof. The entire cache is confined within the area of this roundabout, so it is easy enough to walk around.
One other note: I hope you have brushed up on navigational waypoints!
Good luck!!