Hey T.
There are lots of good captains in Utila and they almost all pride themselves on finding whale sharks. Rightly so, they are incredible. After finding the sharks, their main job is to keep the guests and sharks safe, and to not drop the guests too close to the shark (sadly, often deemed unimportant).
So, good captains are aplenty. Not as many good divemasters. Unfortunately, what makes a good scuba divemaster does not always go for a good whale shark snorkelling divemaster. My experience that many either do not know the encounter guidelines, or they ignore them. But this is more an issue of training than anything else. They are not expected to be specialists in understanding animal behaviour and wild animal interactions, but by blindly aiming to
just see the shark, they often lose sight of how their jumping/splashing/rapid movements affect the sharks. My research showed a strong correlation between how calm and relaxed the group was (no splashing, motionless/slow moving), and how calm the shark was (not always, but most of the time). By doing this, we often had long, long encounters; with the shark investigating us, and calmly continuing to feed very close to us. We extended our encounter times (i.e. better for the guests and working zoologists) and minimized our impact on the sharks.
So, having said all that, try to ensure that whoever your captain and divemaster are, that they know what they are doing and have
the whale sharks' interests at heart.
In addition, you may find my Utila Whale Shark blog interesting:
Fascinated by Whale Sharks (+fish, +corals...)
Kind regards
Dale Forbes