The world of waters still keeps a lot of secrets to be elicited. Some hydraulic processes are miracles for us still. Engineers, surveyors, hydrographers and scientists want to describe processes they discover. But humans do not have enough senses to read all signals from nature, they need assistance. Oceanographers and instrument manufacturers are keen to invest a lot of money in developments to find the right instrument to formulate a question for an unknown process. How can we proof the process? Sensors and instruments extend the number of human senses and can give answers. What has started with thermometers filled with liquids, humidity sensors containing human hair or, using a coiled up pipe to measure pressure got us to the present stage providing acoustical, optical, magnetical etc. instruments using complex algorithm to convert the physical parameters into reproducible numbers.