He wasn't being investigated for anything, from the answers I heard.

Trump was extremely defensive about the salacious stuff is what Comey said.

who is being investigated are the people tangential or directly involved in Trump's campaign. In Watergate Nixon was not under investigation, clearly he didn't break into the Watergate hotel himself. Trump didn't meet the Russian ambassador himself. Trump won't be under investigation until we know what these people know and then follow the chain of command to the top. When did Trump know, what did he know etc... obviously Trump much like Nixon is trying to kill the investigation before it starts to work its way to the real sharks. It didn't work back then.

In March 2016, right after he had delivered a speech at the Mayflower Hotel urging better relations with Russia.

It's not clear how long or extensive that meeting was, but there was in fact an interaction.

just hadn't gotten that far. Yet.