The Thekkadi Boat accident reminds us of the tragedy that took place in April 2006 in Manaama near Bahrain wherein 57 people including Keralites were drowned. That should have been an eye-opener for us; but the authorities nor people learn lessons.
As far as the boat Jalakanyaka is concerned it is a small vessel designed to float on calm waters. In any floating vessel the horizontal dimensions should match the vertical dimension, that is the height of the vessel should not exceed the width. But from the newsphotos, it should be inferred that this fundamental rule is ignored. In normal floating circumstances, the vessel should withstand such infringements, but when fitted with an engine and made to move at a considerable speed and that too with packed with full load, a slight disturbance in equilibrium will topple the vessel. And that might be what had happened in the case of Jalakanyaka in Thekkady.
An engine propelling from behind and taking a turn causes increased thrust of water against the sides of the vessel. Adding to this additional weight by virtue of passengers on the upper deck added to the centrifugal force that the boat is subjected to and this can cause disturbance of equilibrium and shifting of the center of gravity for the boat. And one never need not learn nautical science to realize this basic mathematics. It will be therefore wise only to withdraw all double decked boat services from tourist spots as it is not something like a double decker Bus that were once plying in Trivandrum or Kochi.