Research into hydraulic loads by a bow thruster. The hydraulic loads on the slope at an open quay construction on piles is investigated. The propeller (bow thruster) jet induces hydraulic loads on the bed, which could result in scour holes and damage to the quay construction. Performed scale model tests provide details about the hydraulic loads in this specific situation with an inclining slope and piles. Measurements are compared to the current engineering guidelines, to include in the design of open quay constructions on piles.