Is it just me that finds this suggestion offensive. Maybe the Indians had already thought about that and since they were already taking g as 10 m/sec^2, they thought that the difference because of sound delay would be insignificant. As would be the variability in speed of sound near the water surface due to moisture.

My response was designed to highlight the equally offensive suggestion that "all the Indians" were metric geniuses, while American students were all slow and ignorant of the metric system.