I am looking at a houseboat as my first investment

Some friends of mine are selling their houseboat. They've put a lot of time and money into it. It was their home and a place for them to do meetings and small retreats. They have two boats and they are selling them both because they are building a house and need the money for the next phase of their lives. This boat is really charming and since I am in the bus tour business as well as being a property manager it seems like a great opportunity for me to do tours on land and sea. Also I can rent it out as an airbnb so it can make money for me must by sitting in the marina. Its really a darling little boat and at 42k seems affordable as a first investment. I've done a lot of research into maintenance, mooring, licensing, insurance and etc and it all seems to pencil out even with modest success with the business side. And if he business tanked, i could give up my apartment and live on it. The monthly expense would be almost the same as what I pay now in rent. The only problem is, I haven't saved a down payment yet and I'm not sure my income is enough to get a loan from the bank. 

I could use some advice from experienced investors about whether this is a good investment and how to creatively finance it. 

My goal prior to this was to save up a down payment and buy a 4 plex once he market goes down. I still want to do that and/or partner with someone to buy an apartment complex. Is this a good first step - or a dangerous distraction ...