Kennebunkport, Maine ? President Bush has a favorite comeback when people say he is like his father. “I got half my mother in me,” he quickly reminds them.

That is not meant as a slight to his mentor and father, whom the younger Bush in his acceptance speech at the GOP convention in 2000 called “the most decent man I have ever known.” It is more of a reference to his mother’s tendency not to mince words, friends say.

Barbara Bush long has been known as a woman who speaks her mind. Bush’s dad is regarded as more of a diplomat.

This Father’s Day weekend, President Bush is spending lots of time with his diplomatic dad.

They are driving golf balls, trying to outsmart fish and, if history is a guide, taking part in lighthearted ribbing that has been going on for years.

In the summer of 1989, Bush, then the 42-year-old son of a president, dared his father to jump into a small cove off the Atlantic Ocean, which laps against the family’s Maine compound at Walker’s Point. The elder Bush stripped to his trousers and plunged bare-chested into the chilly water, winning the dare and its $11 payoff.

Bush has acknowledged that his father, while still very spry, is getting up in years. Last year, while walking down a dirt path at his ranch in Crawford, Texas, Bush volunteered to a reporter from The Associated Press that he knows every visit with his dad could be the last.

John F. Kennedy was the last president who held office while his father was alive.

“The current president is fiercely protective of his father,” said Bruce Buchanan, a political scientist at the University of Texas.

“The blood in this relationship is very thick.”

President Bush, right, chats with his father, former President Bush, as the two fish together off the coast of Kennebunk, Maine.

In many ways, Bush has followed in his father’s footsteps. Yale graduates. Military members. Ventures in the oil business. Avid baseball fans. Their paths to the White House, however, were quite different.

The father was Phi Beta Kappa at Yale; the son was a C-average student. The father was a combat pilot in World War II; the son flew jets for the Texas Air National Guard but never saw combat.

The father’s resume includes stints as an ambassador, vice president, CIA director and Republican National Committee chairman. Before becoming governor of Texas, the son’s career veered off track and he spent his self-described “nomadic years” with a hard-partying crowd.

“This is a guy who has always shown signs of revering his father, but who, as a young man, seemed kind of intimidated by him, or in awe,” said Fred Greenstein, a political scientist at Princeton University.

“Part of why George W. was such a late starter on the road to maturity was that the male role model in his life was such a superachiever that it was hardly worth trying.”

That’s history.

“My guess is that the father now defers to the son and is very tactful about what his suggestions are,” Greenstein said.