That adapter is for connecting a 4 pin trailer to a 7 pin tow vehicle, opposite what you have. If your trailer has a 7 pin connector, it has electric brakes. In that case you must have a brake controller, wired or wireless, for your tow vehicle.
The 7 pin connector requires installing a brake controller on your Bronco. The 7 pin allows using a trailer with electric brakes. Most states require trailer brakes when towing above 3,000 lbs.
However, boat trailers with brakes don't usually have electric ones. Instead they have hydraulic...
Corvettes haven't used fiberglass since 2004. Starting with the C6 in 2005, they use SMC - sheet molding compound. Which raises the question as to why Ford didn't use SMC as Chevy does for the Vette.