* Refraction: The water in the aquarium acts like a lens, bending light rays. This makes objects underwater appear closer and larger than they actually are. This visual distortion makes it hard to judge the depth and distance accurately, making it tricky to grab the object.
* Water resistance: Water is much denser than air, creating significant resistance to movement. Your hand will encounter substantial friction as you try to reach down, making it harder to maneuver and control your grip.
* Pressure: As you go deeper into the water, the pressure increases. This pressure can make it feel like your hand is being squeezed, further hindering your ability to grip.
* Limited visibility: The clarity of the aquarium water can affect your visibility. Even if the water is clear, the depth can make it difficult to see the object clearly, especially if it's small or has a similar color to the aquarium bottom.
These factors combine to create a challenging task, often requiring careful planning and practiced hand movements to successfully retrieve an object from the bottom of an aquarium.