“Blade Air told the Daily Mail the hard landing was likely caused by choppy water from passing boats and Saturday night’s thunderstorm.
‘There were a lot of ferries in the vicinity and there may have been wind and the last second,’ a source at the company said.
‘The waves they create can be a problem as you try to land on the water.’
Blade said the impact cracked one of the plane’s struts - which connects the pontoons to the body of the plane - which also caused damage to one of the pontoons.”
https://www.dailymail.com/news/article-15954475/plane-crash-nyc-east-river-hamptons.html
I had not realized how much harder it is to land and take off with seaplanes.
Then I started reading about it. It is much, much more difficult than landing on solid ground.