"“Aeeeeiiiiiiiiii”, Shauna shrieked, splashing heavily trying to flee the boulder-sized head coming at her. Her stunned scream set off a chain reaction of fear throughout the group – four of us swished about, creating waves in the green, cold water. We didn’t know where to go. The boat was ten meters from us. The shark was much, much closer.
The whale shark swam close enough to touch for a second and then turned into more open water. Its gigantic fin giving a swish that pushed a block of cold water our way. In a pause, we were back to calm. The group remembered what we were doing and righted ourselves, adjusted our masks and snorkels and followed the 5-meter giant into the open water."
Read more at: http://takeyourbigtrip.com/2012/03/25/snorkeling-whale-sharks-la-paz-mexico/