The basic equipment of a sea level station is the tide gauge, that consists of a measuring system which detects and registers this variable by using different systems, like: float gauges, pressure sensors, electrical sensors, acoustic gauges, bubbler gauges, radar and etc.
It is extremely important that GLOSS site measurements be associates not only with redundant measurements of the sea level, but also atmospheric observations and other oceanographic parameters (atmospheric pressure, air and water temperatures, rain, evaporation, wind direction and intensity). It is recommended that continuous GPS measurements and regular absolute gravimetry measurements should be used. They should be carried out in order to monitor vertical and horizontal crust movements.
The sites for the Brazilian continental GLOSS network should: be permanent in order to well represent the open sea conditions, avoiding regions of rough surf or strong currents; avoid fresh water runoff (rivers). They must be away from very active port operations that may damage the station. They must be at adequately deep water; have solid foundation (wharf, pier, jetty, etc) for supporting the station; have insurance against vandalism (station observer or port authority cooperation); and be of ease access for the tide observer and station technicians.
In addition to recording on site, the GLOSS sites should be equipped for automatic data transmission to data centres, by using a regular communications system available. The aim of any tide gauge recording should be to operate a gauge which is accurate to the 1 cm at all times, i.e. in all conditions of tide, waves, currents, weather etc. This requires dedicated attention to gauge maintenance and data quality control. Timing accuracy should be better than one minute, the minimum sampling interval, in all circumstances, should be one hour. Measurements should happen for long periods and must be made relative to a fixed and permanent local Tide Gauge Benchmark, in order to provide long term data sets.
New technology gauges are to be gradually sought, bearing in mind that provided, by definition, less well understood than old ones, and they must always be operated alongside the older ones, perhaps for several years, until sufficient experience has been obtained.