The GCWR on the Raptor is right around 14,250 lbs, so keep the truck itself as light as possible.
And like everyone has already mentioned, a WDH is a MUST! The stock class III hitch is rated to 5,000 lbs and 500 on the tongue - WDH will increase the stock hitch to 11,000 and a 1,100 on the tongue. (Of course, the hitch rating doesnt necessarily mean your truck can pull it.)
You're right on the edge of it's max towing capacity at 8,000 lbs, so stay local, keep your speeds down, empty out your truck of all necessary gear (and people) and you should be fine.
Congrats on your new boat to be.... and Happy Boating!