Use This to Fly a Plane or Steer Your Boat for You

Puzzle 14 of Alliteration Piece of Cake Pack

Question is: Use This to Fly a Plane or Steer Your Boat for You

and the answer is: AUTOPILOT

Word Meaning:

AUTOPILOT — (aviation, nautical) A mechanical, electrical, or hydraulic system used to guide a vehicle without assistance from a human being.

Definitions from Wiktionary.