New Meteorite Crater Discovered South of Haiti

I had an interesting letter recently from Brian Marcks in which he pointed out a submerged structure he found with the help of Google and which looked to him as though it might be a meteorite crater. the important part of his message follows:

I used the Google Satellite Map and followed the trajectory of the crater and scars eastward along the orbit path. Then I found the 80 km crater just off the coast of Haiti. Thus, I think we may be dealing with a Schumaker-Levy comet breakup scenario. Also, the Haiti crater lines up with the long axes of some of the Carolina Bay craters in South Carolina, Georgia and southern North Carolina. I submitted the information on the crater and my hypothesis to the PASSC Database for Earth Impact craters.
Brian Marcks

New 80 km undersea crater South of Haiti submitted by Brian Marcks, at far right

Brian has suggested the name "Comet Atlan" for the name of the Younger Dryas impacting body.
His description of a comet breaking up and falling to Earth in pieces fits some of the evidence, but so far the chunks of meteorite we have recovered from this event have been mostly metallic or mineral in nature, so an asteroid still might be a better choice: we also might be dealing with a swarm of different bodies of different nature travelling together, both stony and icy, but which would be described as a comet to ground observers. This has also been suggested in some cometary swarm scenarios, Marcks and I were also discussing Donnelly's book RAGNAROK in connection to the impact scenario.