Last year I bought a boarding ladder that fits on the front of my trailer.I got it from Sun Tracker.But being an old Fart my self,We both have trouble getting in the boat if we want to get into the water so I took one of my six foot alum. ladders and cut the rear part off. I left the top on and it works great.Our pontoon boat is 24 feet long so I just lay the ladder on the floor or across the rear lounge.
I thought I was going to have to do like you are doing, pull the walk board on board and lay it on the floor.
But I went to Northern Tools and bought a 7 foot walk board that is made for a scaffold, it weights about 35 pounds so it shouldn't be too bad to handle. I thought every which way I could to make it work under the deck, without someone being on the shore to pull it out, and I finally came up with a way that I hope will work for us.
The main problem was getting the walk board to slide all the way out, without someone having to be on shore to pull it out. The further out the walk board gets, the more pressure and friction there will be on the front of the housing and back end of the walk board, making it hard to get the walk board all the way out to the point that it will pivot down to the ground.
I solved this by using a piece of conduit that I can use as a sliding fulcrum to hold the front end of the walk board up, while pushing out
with the conduit pipe and take the pressure off, so it will slide all the way out. I haven't built this yet, but this is what I plan to do. I plan to use PVC pipe as rollers in the housing and hopefully that will work.
I have thought of several ways instead of the PVC pipe rollers, such as using small wheels. I still haven't ruled that out yet, I am open for suggestions.