"It's really exciting and it is very special to be here," said Phil Mickelson Sr.
This started out as a business trip for Mickelson Sr. He owns the company that makes this handy periscope device that allows spectators to see over the crowd.
On Sunday, most of them will be used to peer at his son, who's in the lead going into the final round. It is also his son's 43rd birthday and it's Father's Day.
"Anytime your children do something that is really exceptional and successful, it is special for you," said Mickelson Sr.
Mickelson also won father of the year points this week for attending his daughter's grade school graduation and then flying all night to be back at Merion for round one.
Maureen McLaughlin made this special hat in his honor.
"He's just always happy, always has a smile on his face. He went home for his daughter's grad, what an honorable thing," said Maureen McLaughlin.
Mickelson's dad says he doesn't have to offer his son any fatherly words of wisdom before his round today.
"I think what I always say when he's going to go play is, 'Have a good time.' I think you'll have a really good time if you're doing well," said Mickelson Sr.