Disintegration of several ice shelves along the Antarctic Peninsula demonstrates a mechanism that involves the conversion of a contiguous ice shelf into an expanding plume of ice-shelf fragments that spreads rapidly across the ocean surface. The growth of surface area and energetic expansion are hypothesized to be driven by gravitational potential energy release associated with iceberg capsize and break-up. Here we investigate this process using a water tank filled with plastic icebergs scaled to represent a laboratory analogue of an expanding plume of ice-shelf fragments (icebergs). Our experiments suggest that hydrodynamic pressure within the water separating neighbouring icebergs is sufficient to couple the motion when their separation is comparable to the iceberg size. This allows one iceberg’s capsize to initiate a ‘domino-like’ effect, where the entire array will subsequently capsize in the same direction and expand across the water surface. Our experimental results motivate the suggestion that cooperative iceberg hydrodynamics is a process that enhances the expansion of ice-shelf fragment plumes during ice-shelf disintegration.