"I live amongst the mangroves and I haven't seen the strand yet that could prevent a tsunami wave like that."
No one said prevent -
"When a tsunami comes in, it first hits the coral reef which slows it down, then it hits the mangroves which furthers slow it down. It may get through that but by then a lot of the energy has already been dissipated."
I happened to live in SEA for 15 years - and saw the destruction of the mangroves - beachfront development in their place.
Reminds me of people in the US living in flood plains and wondering why me?