The measurement of the depth regards the instrument or the sea-floor and is fundamental to reference the location of the measurement. The simplest way to measure the depth of the measurement is to mark the wire or rope to which the instrument is attached and measure the length used. The more accurate way is to calculate the water pressure at the instrument level and convert this to a certain depth.
Oceanographic instruments give important data about tides and currents and the water condition characteristics such as chemical composition and salinity. Oceanographic instruments can be also used to forecast the weather conditions, natural calamities like hurricanes, typhoons, and tsunamis and a myriad of marine life. The data collected from these devices can be shared with scientists all over the globe using satellite communication and computer networks.