I just booked a trip to Utila in September.... I (like everybody else who goes there) am hoping to swim with a whale shark. Does anybody have any experience with this. I currently use a Canon S1 IS with a DC20 Housing, but no strobe. Will it be needed? My understanding is most of the time, you snorkle with them anyway.... I'd like to have a strobe by then, but i have to pay for the trip first so we'll see. Any adivce you have about this, or utila in general would be great.