The Chesapeake Bay crater is the largest impact crater in the US. The meteorite that struck Earth an estimate 35 million years ago cause water and rock to splash all over the entire East Coast, creating a crater larger than Rhode Island and killing all regional marine life. This impact has helped form the river patterns seen in the area, as well as the Bay itself.
When I first learned that water doesn’t really slow down an asteroid impact, I was surprised. It turns out that the kinetic energy of larger impacts is so great that most of the water is vaporized instantaneously and has little effect on the velocity of the meteorite. This makes it so that, particularly in more shallow water, a crater from an impact like the one in the Chesapeake Bay looks very similar to a land impact of similar magnitude.