Aqua-dock spacer discs are designed to ensure you always have an even and level surface to walk on, even with odd shaped pontoons. Each module has a moulded tab on the corners, which is set to a specific height. As you assemble the pontoons the tabs interlock and are secured by a pin/bolt to secure the pontoons together.
In instances where an odd number or unusual shaped pontoon is required you may require a spacer, such as whenever there are less than four modules conjoined, also in instances near pontoon edges and internal corners. A spacer disc is used to replace the absent corner tab and ensure that a level pontoon surface is maintained.