A grandfather and his seven-year-old grandson were fishing near Charleston, South Carolina when they were surprised by a playful dolphin that swam up to their boat and showed off for the pair.

The dolphin can be seen flexing its fins as if to imitate the boy clapping, as well as nodding and bobbing for fish.

"Hi! How are you?" asks one man on the boat to the dolphin.

"Look at that, that is something, huh?" says another man as the inquisitive dolphin looks in the direction of the fisherman.

The video was filmed by granddad Bill Roettger.