Which of the following should you do to prepare for heavy weather?

Preparing for heavy weather involves taking precautions to ensure the safety of the crew and the integrity of the vessel. Donning life jackets and harnesses is essential because it significantly reduces the risk of falling overboard in rough conditions. Reefing the sails is equally important as it reduces the sail area to better match the wind strength, minimizing the heeling of the boat and preventing damage to both the sails and the rigging.

In heavy weather, maintaining control of the vessel is critical, and these preparedness steps are the best way to manage that control while also ensuring crew safety. The other choices do not address the necessary safety and control measures as effectively as this option. For example, turning off the engine and lowering all sails could leave the vessel unmanageable. Increasing sail area would be the opposite of what is advisable, as it would make the boat more difficult to handle and less stable. Finally, making a complete turn in the opposite direction could lead to confusion and loss of control rather than providing any benefit in handling rough conditions.