The USCG Float Plan is a state-of-the-art lifesaving device that is used by search and rescue personnel to assist in reducing the search area in order to locate you in the shortest amount of time possible. It is also guides and directs the holder of your float plan on exactly what to do via the included Boating Emergency Guide.
The answer is simple... there are just too many facts that need to be accurately remembered and ultimately conveyed in an emergency situation. Without a float plan you are counting on someone else, a friend, neighbor, or family member to remember detailed information that rescue personnel need in order to find you. Information that can make a difference in the outcome.
Don't think for a minute that this is a device only for those with big expensive boats. The USCG Float Plan is equally effective for the owner of a 10 foot kayak or flat-bottom skiff as it is for a 48-foot express cruiser, or a 90 foot sport-fishing vessel or luxury yacht.
Typically, the Skipper of the vessel is the individual who prepares the Float Plan. However, any member of the crew can be assigned the preparation and filing duty. If you are a crew member, coordinate the preparation and filing of the Float Plan with your Skipper.