He was probably thinking that paying 4% interest makes a whole lot more sense than using his own money that is easily earning 3-5 times that if invested.
Probably also thinking that boats really aren’t depreciating right now. Case in point I could sell my 2014 Malibu with 700+ hours on it for right at what I bought it for new.
And most importantly he’s probably thinking that it’s his money, and he can spend it any way he wants, and not have to worry about what anyone else thinks.
But that’s just my guess……