Not MINE - (I dont' even have a boat house) - but IF I did, I would absolutely look to get one of these/make my own. I've looked into this and you could also do this with your lift on your dock as well. Should note that when boating all day, the decking will be submerged all day long which is where Azak and Lumberrock products that other people have suggested come into play as they can withstand being underwater.
https://www.youtube.com/watch?v=flR6gJOorLg
BIG advantage from my perspective is safety with young children and pets. All it takes is a split second for a young child to slip between the boat and the dock with the boat bouncing back and forth and that could be a devastational outcome... Rare - sure.
Other advantage here is that is allows you to clean under your boat, plus I love the look personally :-)
Picture of a different one: