One couple got some added excitement during their 20th anniversary vacation. Being chased by killer whales.

Rich and Laura Howard thought diving and photographing sea creatures in Mexico would be the perfect way to celebrate their anniversary.

What they weren't expecting were some very large, powerful and fast Killer Whales - also known as Orcas or Orca whales - to join the celebration.

This video explains more about why the killer whales chased the fast moving boat.

The Howards are glad the killer whales were playing a game of chase. If the whales were hungry and decided to capsize the boat and eat those on board, there wouldn't have been a 21st anniversary celebration for this couple.