The Brits were very clever when the designed the “dambuster” bomb in WWII.
Their experiments showed that instead of attacking the reinforced concrete of a dam directly, it was more efficient to have the bomb hit the water side of the dam and then sink.
When the device detonated the massive amount of water behind the bomb/dam would focus the explosion against the concrete. The efficiency was increased many fold versus an explosion in the air.
Exactly correct.