Diver ID Please

Hi,

I've really tried to work this out myself but am just not confident enough. Please help me work out what these three birds are. I'd be grateful if you could also explain the reasoning so I can try to educate myself as I'm annoyed that I'm having to ask and can't work it out myself Weary

I thought the one on the left of the two was Red Throated but confused by the one on the right.

One on its own I thought was Great Northern.

Knowing my luck, none are divers at all Smiley

Thanks in advance,

TM