An incredible exposed prop motor that can be lifted to various levels to maximize/minimize contact with the bottom. They are really best for weeds. I was amazed at how much abuse they take without showing it.
My nephew's boat and he was actually running a Mud Buddy brand motor. 35hp and air-cooled.
We ended up by-passing the cluster at 20-mile and went up Placer. Only one other boat up there and we only heard them briefly.