Propeller plastic trim question

[benchmark]

Does anyone know why these 2 propellers have these small strips of plastic trim on each blade?

 

[jrudge]

What Boat. ? Is it fast ?

Planes have leading edge devices to improve the laminar flow of air over the wing and I wonder if this is trying to do something similar. Smooth out the flow in some way.

 

[Bandit]

By altering the strip you can effectively adjust the pitch of the propeller.

 

[Portofino]

By altering the strip you can effectively adjust the pitch of the propeller.

Correct , I would like some method of measuring the load too ,sos not to prematurely knacker the engines if diesels
http://veempropellers.com/interceptor-technology/

 

[benchmark]

Interesting. Thanks for the answers, i never imagined that one could change the pitch of a prop that way.