I'm starting to believe that Rayleigh is a little more than a father figure to Boa and is literally her father or grandfather.
Honestly, Rayleigh is not a guy that gives a shit about a lot of things. We know that he care about some people but usually he don't try to stir the waves and make a move unless provoked. Except when it comes to Boa (and her sisters).
At the same time, we know that Boa hated men before meeting Luffy. But she always seems to be happy meeting Rayleigh. Even in this chapter she acts like a sad kid with his grandpa, totally defenseless.
I know that people like to think that Mihawk is related to him and Shakky but I think Boa (and her sisters) could take the position.
Shame that part of the fight between Boa and BB got cut.