This is the Narrowboat Chestnut X
It’s actual name is Chestnut Ten; it was the tenth boat built by Chestnut Marine Ltd. However, to add a touch of class the builder decided to use Roman numerals in the name, which would have been fine for boats 4 (IV) or 8 (IIX) or maybe 7 (VII), as everyone would recognise Roman numerals. I have lost count of the times we have been asked “what does the X stand for?”