it is a rubbish clue but beach balls looks good. it's all to do with beach and strand having several meanings some of which are synonyms of each other. e.g. they can both mean a pebbly/sandy shore. beach can also mean to run or haul a boat onto the beach. strand can mean the same, as like when whales beach or strand themselves. in this case the balls are beached or stranded. like I said a crap clue.