That strange vibration we first noticed leaving Delaware City headed to Cape May...got progressively worse yesterday...and caused some problems at docking. We called a mechanic, who referred another mechanic who came right over. He analyzed the engine compartment and called in his "diver". Diver arrived shortly thereafter and presented us with a beach ball sized glob of plastic fishing net he dislocated from our starboard prop shaft.....woo hoo, easy fix! Not cheap...but easy!