For me, there is nothing more disappointing to a family than working hard to get out of the house, drive to the launch or the mooring point, only to find out that one important item was forgotten. It's small consolation that we remembered the 500 other items needed for the day.
Executing checklists adds almost no time to the process. I put mine on a clip board and check things off as I go along. Then I check before I leave for things that haven't been checked.
My worst incident of poor organization happened on the road. I had just pulled my 26x out of the water. As per normal procedure when the nose of the boat isn't to the trailer rubber, I drove and put the brakes on. The boat slid forward. I retightened the trailer holder straps.
I then drove to a strange sound. Sounded like a can in the bed of my pickup truck rolling around. I drove about a mile then someone beeped their horn and flashed their lights.
Turned out that the center board had dropped down. I had not secured it. Yes I know that should not happen, but it did. The factory blamed me for stopping too quickly to nudget the boat up. They are probably right.
Now, I've added 'secure the center board' item to the retrieval checklist.
For me it's not that 500 times that I use a check list and really don't need to that is of concern, it's the one time I forget something because my brain and memory are less than perfect.
Rick
www.trailersailing.com