John Chroston, a biology teacher at Falkirk High School, Scotland, was one of the few tourists present during the Indian Ocean earthquake able to recognise tsunami warning signs and prompt a beach evacuation. (Another foreigner with the right knowledge was British school girl Tilly Smith. Some villages in Indonesia had local knowledge that alerted them.)

Chroston, then 48 years old, was holidaying at Kamala Bay, near Phuket, Thailand, with his daughter Rebecca and his wife Sandra Adams, a professor at Stirling University. He was swimming when the sea receded, and instantly recognised the early-warning sign for a tsunami. He ran up the beach, sounding the alarm, gathering up his wife and daughter.

With the assistance of a Thai doctor, Harpreet Grover, Chroston persuaded a hotel shuttle bus driver to turn his bus around and take passengers to high ground. The bus stopped to pick up a few Thai women and children on the way, and was at one point engulfed by the wave, but managed to pull through and reached high ground.