The U.S.S. Flagg was the granddaddy of all play sets, one of the Holy Grails of G.I.Joe collectors.
Or so they say...
Personally, I'm not sure it even exists. I think it's an urban legend.
But, I won't let that fact that I didn't have it stop me from making miniatures.
For Keel Haul, I used the Heroclix Dick Grayson. I think what makes this match really well is that he's talking on his radio and the U.S.S. Flagg came with a radio speaker as part of the toy. That's synergy!