I've made a few houseboats it's one of my favourite things to to. I have 2 in Sulani and one on a custom made lake in Old New Henford. They're all in the Gallery. I made a small marina in Sulani for one of them but after building it I looked through debug and found so many things that I could have used to make it better such as yachts and other boats. I'd like to see things like this added to the game without needing to use debug. Sims tend to travel through debug items as they aren't recognised as objects.
I'd also like the tools to be able to build a more realistic yacht shaped houseboat on console. Maybe premade bases like we have with foundations and platforms. A new world with more ocean lots would be great too. But I'd also like to be able to add narrowboats too, I used to have holidays on them in the UK and absolutely love them. So a world with canal lots that we could build on would be great.