This Blue Dot float has some unusual attributes.

First, it's 3 inches in diameter.  In my experience, there seems to be a far higher frequency of 2 inch floats with blue seals.  Next highest frequency of blue dot would probably be 4 inch floats.  I've got several 3 1/2 blue dots but this is the only one that's 3 inches in diameter (9 1/2 inches in circumference).

Second, there's an amber green or olive swirl that wraps around the equator of this float.  There are also some wonderful glass swirls.

Next, this float has an inclusion that looks like it could be a kiln stone.

Finally, the seal has some darker cobalt blue streaking in it.

This is not your typical Blue Dot.  I think it's quite unusual and rare. 

It has great provenance from ex-Woody Woodward collection.