Who's RH? I figure your guy is GG (Gershwin) and RR is Rodgers. I can't imagine Gershwin arranging Rodgers.
In any case, my guy is RRB, Robert Russell Bennett. He arranged for about 300 musicals, or so some web site claims. Your favorites are likely on the list. Of his approximately 200 compositions, Suite of Old American Dances and Symphonic Songs for Band were on the Fennell-Eastman recordings that inspired this thread.
There's a pretty well known arrangement of music from Porgy and Bess by Bennett, better known than Gershwin's own till possibly recently.
The sea-going hints refer to Victory at Sea, the TV series with music by Rodgers. Rodgers gets credit as composer, and Bennett as arranger and conductor. There's some question about how mush Bennett actually WROTE. The 26 episodes have music running CONTINUOUSLY in the background, when not in the foreground. I've watched the series more than once. It's well written and edited, but without the music it would be hard to take in total. If you get a chance to see any part of the series, you will probably want a disc of the music. It's quite impressive, especially when the visuals have been experienced.
DS for RRB, RR, GG, and whoever RH may be.