Abstract: This invention relates to a variable trim trimaran in which side floats (2) are provided that are connected to the central hull (1) by means of devices (3, 5) that allow them to shift vertically, wherein a deck structure (4) is provided that is connected to the central hull (1) and is so shaped as to cover at the top portion said side floats (2), so that they come to belong in the general outline of the trimaran itself.