My 44' tricabin came with what I believe was original equipment Marquip 5 step stairs that fastened to the boat with special fasteners (mounted permanently on the boat on both sides). The bottom of the stairs is on wheels so it can move with the boat as it moves, Including up and down. Marquip is still in business, and they want a fortune for replacements. What I did was buy an extra set of fasteners from them and mounted them on a 4X4" wood platform bolted to the floating dock. That way, they didn't have to be disconnected every time we went for a ride, which is every week!
I also bought a Marquip ladder (used, for a few hundred $) from Sailorman (Fort Lauderdale, FL) that I keep on the boat for when we were out cruising to other marinas, restaurants, etc. It can be installed with quick release pins in a matter of a couple minutes. I have found this to be a very good system. The steps have special pins that are bolted to the boat on the side rails to store them when traveling, but for a short, temporary hop, the ladder is much quicker and easier to deploy.
Hope this helps. PM me if you want more information and pictures. By the way, when I went to Sailorman's store, they didn't have the ladder. They took my name and number and put them in their computer. Lo and behold, we got a call a few months later and they had come across the ladder I wanted. It was not in perfect condition so I had to do some repairs and refinishing. But I got the ladder at a CONSIDERABLE savings from what Marquip wanted new. I even did some modifications. It was a five step ladder. Longer than we normally needed. I cut the bottom two steps off with a hack saw, but made stainless tubes that will fit inside of the original tubes and fasten with pins, so I can add back the two steps if I ever need them!