I too have always wondered if there were any pics of the SC. I know that there aren't any of Titanic's, but surely at least one must exist of Olympic's. Also, What was Britannic's used for during the war?
I know of no photos but there's a drawing on page 138 of The Birth of the Titanic by Michael McCaughan. The court was 30 ft long and was two decks high, with a spectator gallery at the end opposite the back wall. In 1912 the game was often called racquets and this term might be useful in your search.
In official White Star publicity, it is depicted in a cutaway view of the ship as a tennis court, complete with nets.
Was this an impossibility or could the courts have been dual purpose? I'm trying to figure out what 30 feet looks like in my mind!
The court was only 30' (9.144 meters) by 20' (6.096 meters) and I think 16'6" (5.0292 meters) high. I think it's a bit small for a tennis court. I've never read any accounts about it being used as a tennis court. Anyone know?