Support device for at least one instrument on a tower for loading and/or offloading a tank of a ship intended to contain a liquefied gas

The invention relates to a support device (100) for at least one instrument on a loading and/or offloading tower of a tank of a ship, the tower comprising a plurality of vertical masts linked to one another, pairwise, by struts (531) extending on an axis called strut axis (X), comprising: a distal portion (101) extending on a first axis (Y), the distal portion (101) being terminated by a first surface (102) capable of forming a first surface contact with a strut (531) extending on its strut axis (X) substantially at right angles to the first axis (Y), the first surface (102) having, in a configuration of installation, a degree of freedom in rotation about said strut axis (X); a proximal portion (103) extending on a second axis (Z) substantially at right angles to the first axis (Y), linked to the distal portion (101); a fixing surface (104) having, in the configuration of installation, a degree of freedom in rotation (105) about the second axis (Z) and a degree of freedom in translation (106) on a third axis