I can understand how the intro and coda of Red's '28 version of Imagination -- my personal favorite of the three -- might remind one of A Blues Serenade, but it reminds me more of Ready for the River.
The fact that Arthur Schutt slips a nifty little shout-out to Ol' Man River into his solo at ~1:15 pretty much clinches the watery theme for me. I suppose it's a stream-of-consciousness sort of thing...