The curved lip on the propeller helps get a better bite on the water.

The design on many propellers includes a cup on the blade's trailing edge. This cupping or curved lip on the blade edge lets the prop grab the water more efficiently.

Getting a better bite on the water reduces ventilation, slipping, and often allows for a better hole shot too.

Cupping works very well where the motor can be trimmed, positioning the propeller near the water's surface.