In mixology, what is floated on top of a screwdriver cocktail to turn it into a Harvey Wallbanger?

Grand Mariner not Grand Mariner

new info for me.thanks

alaalias, Makes great truffles.

l remember asking my uncle, why he had a hole on his wall, when I was 12 years old. he said, that right there is a Harvey wallbanger.

Has anyone noticed "Grand Mariner"?

I prefer a Freddy Fudpucker myself...

Likeable master, Henry knee knocker (after a few!)