Stephen Keller 31 August 2011 propeller accident report in San Jose Mercury News that dramatically understates the number of propeller fatalities per year.
Houseboat Propeller Regulation Proposed and Withdrawn by USCG: Analysis by PGIC
History of Boat Propeller Safety
Mitigating Boat Propeller Injuries & Fatalities Chart
Four Volume Review of the Boating Industry’s Boat Propeller Guard Product Liability Defense