Marley the dog pulls off a spectacular water rescue at a Wellington beach

A heroic dog has pulled off a spectacular water rescue at a Wellington beach.

Marley the Labrador was out on an afternoon walk on Monday at Petone Beach when he noticed a small dog drowning in the waves.

Completely untrained, Marley jumped in and saved the fox terrier from disaster.

"Marley just randomly jumped off the footpath and swam out to the dog. And when he got out to the dog, he nuzzled into him and said g'day," his owner Steve Sheppard told Seven Sharp.

"He went out to the seaside because he was drifting out to sea and started pushing him towards the shore."

Seven Sharp reporter Julian Lee caught up with Marley and his owner to hear more of the amazing tale in the video above.