The Puretic power block is a special kind of mechanised winch used to haul nets on fishing vessels.
While he was working as a tuna and sardine fisherman from San Pedro, California, Puratić started thinking about the difficulty of hauling seine nets.
The original power block he designed was essentially a simple winch which used a V-shaped roller coated with hard rubber.
It is possible to fish in rougher weather with the power block, because the steady force exerted by the net stabilizes the vessel.
[5] These fisheries haul huge schools of tuna, salmon, herring, sardines, anchovies and menhaden from the sea,[1] accounting for a large part the world's total fish catch.
[7] In 1975 Mario Puratić was given the National Inventor of the Year Award by the Intellectual Property Owners Education Foundation for his invention of the power block.