Bruce Porter, struck and killed by boat propeller while diving off New Zealand on 7 February 2014. Image cropped from one in Nottingham Post we saw used by others as well. It may be a Facebook image.
Houseboat Propeller Regulation Proposed and Withdrawn by USCG: Analysis by PGIC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