Do you mean this Saturday night?
That's probably too short notice to book one of the pontoon boat cruises, but it's worth a shot.
I would *definitely* call Shades of Green and ask someone there this same question. My suspicion is they might be able to help you whip up something in one of their restaurants or down by their pool?
A totally free idea, is this: Whatever the honorees favorite ride is, the whole group has to go ride it together a few times in a row. "Space Mountain Marathon" or something like that. Get him a t-shirt from that ride/about that ride if there is one.