This 14 inch marked float measures about 45 inches in circumference. 

It's marked with WP #7 'Se' セ from the Otaru Glass Company. The type of stamp used is the typical kind.  It's a small sized stamped that was deeper pressed into the glass on the seal button.

The float itself is very light for its size which is the result of the millions of tiny bubbles in the glass.

This float was originally acquired in Hawaii around 1945 by a woman that was stationed there as a nurse at the Army hospital near Pearl Harbor.  She brought it back with her to Wyoming when she retired from the service.  I had the opportunity to purchased this wonderful float from her estate.  Beside having an interesting provenance, this float is just really nice!