By Kimberley Dadds

PUBLISHED: 08:09 EST, 18 August 2013 | UPDATED: 08:17 EST, 18 August 2013

She's spent the last few days unwinding on holiday in Hawaii as part of her 38th birthday celebrations.

And it seems it's doing wonders for Charlize Theron as she continues to let her hair down during the break.

But she's making sure she doesn't get bored of the usual sunbathing holiday activities by keeping occupied with some water sports.

The Monster star tried out a spot of kayaking and showed off her skills with her oars as she spent the morning on the water.

Charlize, who turned 38 earlier this month, looked delighted as she worked up a sweat gliding along in the boat.

She first of all showed off her beach body in a one piece stripey swim suit.

Theron completed her beach ready look with a trilby straw sun hat to protect her from the hot rays, while she wore a pendant around her neck.

But she later got ready to get wet as she covered up her swimwear in an electric blue rash top.

Charlize still wore her sun hat and added large dark sunglasses to the mix as she carefully stepped in to the kayak.

And she was obviously enjoying the activity as she smiled widely while being joined by the instructors and her girls pals.

The Oscar-winner has been taking a well-earned break in Hawaii with her 17-month old boy Jackson, who was last seen amusing his mother by trying to pull a pair of snorkelling goggles over his head unaided earlier this week.

But while Jackson’s efforts kept Charlize entertained, she got down to the serious business of teaching him how to swim on Wednesday when they were sported paddling in the warm coastal waters.

Charlize has spent much of the last week in Hawaii while she celebrates her birthday, which fell on August 7, and has devoted much of her time to teaching Jackson how to paddle with the aid of armbands.