which safari boat did you go on? i worked a year on safari boats here in Maldives, Rani, Discovery 1, and Sultans of the Seas boats. never had a problem with groups scaring off marine life. we have seen whale sharks, mantas, huge shoals of fish, all on scuba. (perhaps your dive guide didn't know where to take you
South Ari Atoll, i am going there on 3rd June for 4 nights getaway. they see whale sharks there 280 days of the year... didn't you see any?
i am going to holiday island.. just up the "road" from White Sands. (did you stay in the water village or in the bungalows?)