She seems a lot less happy about it than your other cat... but she's probably a little more flipped out by the movement and splashing around. We've seen that with our cats and giving them a bath... they are far more worried by the splashing and SOUND of the water than by actually being IN water.
=^..^=
I think you are right. The sights, sounds and smells of Belize are probably scary to them as well.