The problem of water contamination in petroleum products is widely prevalent during its manufacture, transport or storage. Intentionally or unintentionally, water may find its way into the petroleum reservoir and the direct height of the petroleum surface then is not the true measure of the amount of the product in the reservoir. In such a case, it becomes necessary to take a dip in the tank to investigate the presence of water if any and, to ascertain the petroleum-water interphase not only to estimate the physical stock of the product but also to avoid the serious risk of the water being accidentally picked up and delivered with the product. The AQUADIS Water Finding Paste serves the purpose to measure or detect the presence of water in the petroleum.