Profound Outdoors makes a floating worm. 7 1/2" called the "Big Bear". Last time I looked they were sold out, however. A lot of the Elaztech worms float. Z Man as suggested and there was a KVD Strike King version a couple years ago. Don't mix with other worms or leave in car on hot day, they fuse.
As far as I know, an Elaztech worm can not be used with a screw keeper. Offset wide gap would be Mu suggestion.