Can somebody ID this bird.....never seen it before. It was quite the diver. Down for half a minute and up again 30yds away. Thanks guys!

i am gonna say baby coot

I'd say no to a coot. They don't dive that much just for the heck of it and they are rarely ever alone. Plus there shouldn't be any imature coot around this time of year. Also coot don't lay their head back like this bird, they always have their heads forward or straight up.
It is a pied-billed grebe. We see a couple of these every year while hunting. Usually is two of them together but sometimes only one. Theyjust swim and dive around all morning while you are shooting. Nothin bothers them to much. They are illegal to shoot in WI.WCL

Here is a couple pics of grebe. They are a very tiny bird. Smaller then a teal. Great divers as you mentioned too.

more commonly called a Dive-Dapper in Texas.........

The actual name for this bird is a pied-billed grebe. not even part of the duck family.

yea i have to agree with everyone else it is a pied-billed-grebe

another nikname is the Helldiver