A guy at the boat yard has copied my drive shower and his doesnt flow - mine does.

Not sure of his installation but I understand he should locate stardoard side for L/H prop and Port for R/H.

What about the angle of the inlet - mine is about 15 degrees, one advertiser promotes 80 degress, his is 45 degrees as cut.

Also considering cavitation do you locate / drill rearwards of prop tips and how close to the sides.

If there is tech right way - let us know.