Embodiments relate to fluid baffles and parts and kits for making such baffles. For example, some embodiments relate to a fluid baffle for use in a tank, where the baffle comprises: a body defining an interior volume and defining a plurality of fluid passage apertures at spaced positions around the body to allow fluid to easily pass into and out of the interior volume; wherein the body comprises a continuous wall that defines a plurality of convex regions spaced from each other around the body and defines concave regions between the convex regions.

A fuel tank of or for an aircraft. The fuel tank has an inner hull bordering a tank space to be filled with a fuel, and an outer hull encasing the inner hull with an insulation layer in-between, the insulation layer thus separating the outer hull from the inner hull. The fuel tank further has an internal reinforcement structure extending from the inner hull into the tank space, the reinforcement structure including at least one truss and may also include at least one anti-sloshing wall. Also an aircraft with such fuel tank.