Swimming lessons!

I got a desperate phone call this evening- "I've made a real mistake! I've signed up for a triathlon on Saturday with a 1.5k swim but I don't know how to swim!"
So I went along to the pool to give a brief lesson in the basics.. My favourite moment was when he finished length two, all breathless and bugeyed behind his goggles and looked at me with terror- "I've done a terrible thing!!"