The characteristic length of a very large floating structure (VLFS) refers to the area influenced by a local perturbation, such as a concentrated load. Previous studies have revealed that the relative sizes of VLFSs over their characteristic lengths significantly influence their structural behavior. The current study proposes two analytical models to assess the influence of local perturbations on modular floating structures and quantify the characteristic lengths. The bending model considers finite connector bending stiffness, while disallowing the connector shear deformation. On the contrary, the shear model considers finite connector shear stiffness while disallowing the connector bending deformation. Both models assume the floaters to be infinitely stiff. The proposed analytical models are validated by numerical simulations based on hydroelastic analysis, accounting for finite connector bending and shear stiffness.