Mooring assistance device comprising: at least one articulated mechanical arm movable, mechanically fixable at one end to the quay / pier by means of at least one joint connection and provided at the opposite end with a support base on which cleats are fixed ( 11, 12, 13) adapted to hold corresponding mooring lines (11a, 12a, 13a); said articulated mechanical arm comprising at least a first arm and a second arm connected to each other by means of a hinge element configured to allow reciprocal angulation so as to allow extension in length of the articulated mechanical arm; wherein in that said arms (1a, 1b) being respectively provided with a first linear length and a second linear length and are movable, at least along a horizontal rotation plane, between a retracted configuration, in which they are placed side by side in proximity of said quay / pier and an extended configuration in which they define a total length substantially equal to the sum of the first and second length; said device further comprising: - at least one motor capable of varying, by means of suitable mechanisms, the angle formed by the arms (1a and 1b) in correspondence with the hinge element, extending the length of the articulated mechanical arm up to achieving the extended configuration or by folding the arms against each other in the retracted configuration; said motor also allowing the variation of the distance from the water of the movable articulated mechanical arm by changing the angle of the articulated joint at which the end of the mechanical arm is made supportive; - means for connecting and transmitting the motion of the motor, to the articulated arms (1a, 1b) and to the articulated joint; - remote engine control devices, characterized in that the articulated joint is configured to be mechanically fixed on an external vertical wall of the quay facing the boat. at least one articulated mechanical arm movable, mechanically fixable at one end to the quay / pier by means of at least one joint connection and provided at the opposite end with a support base on which cleats are fixed ( 11, 12, 13) adapted to hold corresponding mooring lines (11a, 12a, 13a); said articulated mechanical arm comprising at least a first arm and a second arm connected to each other by means of a hinge element configured to allow reciprocal angulation so as to allow extension in length of the articulated mechanical arm; wherein in that said arms (1a, 1b) being respectively provided with a first linear length and a second linear length and are movable, at least along a horizontal rotation plane, between a retracted configuration, in which they are placed side by side in proximity of said quay / pier and an extended configuration in which they define a total length substantially equal to the sum of the first and second length; said device further comprising: - at least one motor capable of varying, by means of suitable mechanisms, the angle formed by the arms (1a and 1b) in correspondence with the hinge element, extending the length of the articulated mechanical arm up to achieving the extended configuration or by folding the arms against each other in the retracted configuration; said motor also allowing the variation of the distance from the water of the movable articulated mechanical arm by changing the angle of the articulated joint at which the end of the mechanical arm is made supportive; - means for connecting and transmitting the motion of the motor, to the articulated arms (1a, 1b) and to the articulated joint; - remote engine control devices, - at least one motor capable of varying, by means of suitable mechanisms, the angle formed by the arms (1a and 1b) in correspondence with the hinge element, extending the length of the articulated mechanical arm up to achieving the extended configuration or by folding the arms against each other in the retracted configuration; said motor also allowing the variation of the distance from the water of the movable articulated mechanical arm by changing the angle of the articulated joint at which the end of the mechanical arm is made supportive; - means for connecting and transmitting the motion of the motor, to the articulated arms (1a, 1b) and to the articulated joint; - remote engine control devices, characterized in that the articulated joint is configured to be mechanically fixed on an external vertical wall of the quay facing the boat.