In the context of communication through water or any other material, the speed at which information travels is typically much slower than the speed of light in a vacuum. This is due to various factors, including the properties of the medium, the transmission mechanisms, and the physical limitations of the systems used for communication.
When it comes to water-based communication, such as sending signals through fiber optic cables submerged in water, the information is typically transmitted as light pulses. These light pulses travel through the fiber optic cable at a speed slower than the speed of light in a vacuum due to the refractive index of the material. However, even in this case, the speed of light in the fiber optic cable is still significantly faster than the speed at which electrical signals travel through copper wires, for example.
In the context of space travel, it's important to note that water is not used as a medium for sending information between Earth and space. Instead, various forms of electromagnetic waves, such as radio waves or laser beams, are employed for long-distance communication with spacecraft. These electromagnetic signals also travel at the speed of light (in a vacuum) once they leave the transmitting antenna or laser source.
To summarize, water or any other material does not allow information to travel faster than the speed of light. In all cases, the speed of light (in a vacuum) remains the ultimate speed limit for information transfer.