Examples Continued! Because changing the pitch of the propeller's blades changes the performance so much this leads to unique circumstances for each design. Modern day engineering has constructed variable pitch propellers, which allows for unique applications in aviation. Its preferable for planes to have low pitched propellers for takeoff as the extra thrust for fighting earths gravity is useful, however, once at cruising altitude it's no longer preferable to have that extra thrust since it takes extra gas!

Example of the internals of a variable pitch boat prop.

(https://www.nauticexpo.com/prod/man-diesel-se/product-21500-395535.html)