Sean Penn: Shirtless Surfer Dude in Hawaii!

Sean Penn shows off his abs while going shirtless at the beach on Monday (December 30) in Hawaii.

The 53-year-old actor was joined by a pal while doing some surfing.

PHOTOS: Check out the latest pics of Sean Penn

A few weeks ago, Sean sported a plaid shirt while taking a stroll around the neighborhood in Malibu.

Sean recently told the AP that businessman Jacob Ostreicher, who fled Bolivia after money-laundering accusations, was now safe and receiving medical attention at a secret location.

In case you didn’t know, Sean traveled to Bolivia and appealed to President Evo Morales to free Jacob after he spent 18 months in jail.