PURPOSE: To exhibit the protective function against obstacles sufficiently by placing an intermediate bracket between a stern bracket and a swivel bracket.

CONSTITUTION: The lower end of a power trim and tilt cylinder 7 is held rotataly on the lower side of a stern bracket 1, while the upper end of the piston rod 8 of a cylinder 7 is held rotatably on the side of the inermediate section of an intermediate bracket 4. When the piston rod 8 has extended to the uppermost is the state where the propulsion machine has lifted completely together with the intermediate bracket 4 and a swivel bracket 5 and tilted-up and when the piston rod 8 lowers, the propulsion machine will lower to produce the normal travel state.