Final answer:
The correct action to take with a pre-departure float plan is to keep it confidential and leave it with a trusted individual. This ensures your safety, as the plan can be used to locate you in case of an emergency.
Step-by-step explanation:
When preparing for a trip on water, a pre-departure float plan is an important safety document that outlines your itinerary, the names and contact information of your crew, your boat's information, and your planned routes and destinations. The correct action to take with a pre-departure float plan is C) Keep it confidential. You should leave this plan with a trusted friend, family member, or marina staff who is not traveling with you. This way, if you do not return or check-in as planned, rescuers will have a valuable starting point to locate you. It is not advisable to share it on social media, ignore it, or treat it disrespectfully, as it could be a critical tool in ensuring your safety.