Final answer:
When wind direction is toward the dock, it is best to cast off downwind first to better manage the boat's movements and prevent being pushed back onto the dock.
Step-by-step explanation:
Cast off the stern line. Move and secure the bow line to a mid-boat position on the dock. Put the boat into forward gear briefly, and turn the steering wheel hard toward the dock. Increase speed slowly until the stern is well clear of the dock. Cast off the bow line. If the wind direction is toward the dock, you should always cast off downwind first when leaving the dock. This is similar to how airplanes take off into the wind to gain lift more efficiently.
When sailing or boating, casting off with the wind in favor helps in managing the boat's movements better and prevents the boat from being pushed back onto the dock. This is important when considering the forces acting on the boat, such as wind and currents, which are essentially the real-world application of subtracting vectors graphically.