Maybe his name is Chippy Hubble and he is a crabman
I think he is called Mr Hubble by Martin who would of course refer to I'm as "Mr Hubble". To everyone else in town he is known as Chippy or the crabman. That's my theory. Will be interested to see what he is called in S6E1?
Right, yes, that would explain it. I think your theory is correct.
Not sure why I didn't think of it myself.