I always apply the parking brake first before putting my truck in Park when launching the boat. This lessens the strain put on the transmission and makes it much easier to put it in gear. After loading the boat, and ready to pull up the ramp, I put the truck in gear first, then release the parking brake. Problem is, this ONLY works if you have a reliable parking brake, which wasn't always the case in my previous 18 year old F 150. Now, it's part of my routine.