A cleat comprising: - a cleat base portion having a lower extension provided with cleat mounting holes; - an arm portion having a lower arm surface, an upper arm surface and an arm thickness defined by a minimal distance between the lower arm surface and the upper arm surface; - a forward end hook portion protruding from the arm portion, said forward end hook portion having a hook portion upper surface in line with the upper arm surface and a hook portion lower surface, said hook portion upper surface having a forward hook portion edge and said forward end hook portion having a hook portion thickness defined by the maximum distance between the hook portion upper surface and the hook portion lower surface, said hook portion thickness being larger than the arm thickness and a hook portion holding surface directed to the cleat base portion; - a spring biased retaining block slidably arranged on the arm portion between a cleat locking position and a cleat release position, said spring biased retaining block having a forward retaining block surface, said retaining block being spring biased away from the cleat base portion into the cleat locking position, said retaining block being arranged to be slid against the spring bias in a direction towards the cleat base portion for bringing the forward retaining block surface into the cleat release position at a release distance from the forward hook portion edge; characterized in that the arm portion protrudes from the cleat base portion in an arm portion extension direction substantially perpendicular to the cleat base portion, and in that said cleat comprises: - a guiding profile integrally arranged at the upper arm surface, said guiding profile extending in the arm portion extension direction, the guiding profile protruding with a guiding profile height above the upper arm surface; - the spring biased retaining block is slidably arranged on the guiding profile between the cleat locking position and the cleat release position, said spring biased retaining block having a forward retaining block surface, said retaining block being spring biased away from the cleat base portion into the cleat locking position in which the forward retaining block surface is positioned above the forward hook portion edge, said retaining block being arranged to be slid against the spring bias in a direction towards the base portion for bringing the forward retaining block surface into the cleat release position at a release distance from the forward hook portion edge; said spring biased retaining block extending at a retaining block height above the guiding block height. - a cleat base portion having a lower extension provided with cleat mounting holes; - an arm portion having a lower arm surface, an upper arm surface and an arm thickness defined by a minimal distance between the lower arm surface and the upper arm surface; - a forward end hook portion protruding from the arm portion, said forward end hook portion having a hook portion upper surface in line with the upper arm surface and a hook portion lower surface, said hook portion upper surface having a forward hook portion edge and said forward end hook portion having a hook portion thickness defined by the maximum distance between the hook portion upper surface and the hook portion lower surface, said hook portion thickness being larger than the arm thickness and a hook portion holding surface directed to the cleat base portion; - a spring biased retaining block slidably arranged on the arm portion between a cleat locking position and a cleat release position, said spring biased retaining block having a forward retaining block surface, said retaining block being spring biased away from the cleat base portion into the cleat locking position, said retaining block being arranged to be slid against the spring bias in a direction towards the cleat base portion for bringing the forward retaining block surface into the cleat release position at a release distance from the forward hook portion edge; - a guiding profile integrally arranged at the upper arm surface, said guiding profile extending in the arm portion extension direction, the guiding profile protruding with a guiding profile height above the upper arm surface; - the spring biased retaining block is slidably arranged on the guiding profile between the cleat locking position and the cleat release position, said spring biased retaining block having a forward retaining block surface, said retaining block being spring biased away from the cleat base portion into the cleat locking position in which the forward retaining block surface is positioned above the forward hook portion edge, said retaining block being arranged to be slid against the spring bias in a direction towards the base portion for bringing the forward retaining block surface into the cleat release position at a release distance from the forward hook portion edge; said spring biased retaining block extending at a retaining block height above the guiding block height.