Golf course visitor

Accompanying Mr F on the golf course today ( I am a saint) we saw this water monitor. Not the best shot as I had to cross a fairway before it made it's getaway.
This shot doesn't give any idea of size, but he was approx 5 ft long. When he entered the water he tucked his front legs up on his back and using his tail and back legs propelled himself at quite a speed through the water.

They are quite pre-historic looking and I wasn't too keen to get too close.