Did you actually know that grasshoppers avoid water surfaces?
Scientists have found out recently, that Locusts (that is the name of grasshoppers in the swarming phase) avoid to cross over water surfaces while on their voracious flights; which can be understood because there are no landing or feeding possibilities. However, they also found out that the animals prefer to fly over dry land rather than over wetland.
The grasshopper on our diving boat was obviously intimidated and moved only little.
The reason is that the originally unpolarized sunlight is reflected from the water surface and becomes partially polarized. All insects can identify polarized light (which is a bundle of light beams consisting of almost equally aligned waves) and they deviate in their direct route. It is thus not only the wind that dictates the direction of the swarm.
By the way: Fish also have the ability to perceive polarized light (which brings up the question if that means that they don’t like water either).