Outboard Marine Corporation (OMC) cost figures on Project 443, and early 1980’s project to develop a propeller guard to protect people and minimize performance (top speed and fuel consumption) impacts per some OMC experts sometimes.
Houseboat Propeller Regulation Proposed and Withdrawn by USCG: Analysis by PGIC
History of Boat Propeller Safety
Mitigating Boat Propeller Injuries & Fatalities Chart
Approaches to Prevent Outboard Motors From Flipping Into Boats After Striking Floating or Submerged Objects
Why Outboards Used in Bass Tournaments Disproportionately Break Off & Flip into Boats Compared to Other Outboard Motors
Four Volume Review of the Boating Industry’s Boat Propeller Guard Product Liability Defense