There is an emerging trend in the Far East of using idled container ships to store empty shipping containers. Some liner companies have run the numbers and found that it is cheaper for them to pay a handling fee to have empties moved onto idle ships than it is to pay daily per-TEU storage fees at the ports. The cost-benefit analysis to this approach only works if you plan to be storing the containers for an extended period. This doesn’t indicate a very optimistic outlook on the liner company’s part.
However, it could be a significant cost savings. An 8,000 TEU ship would hold, you guessed it, 8,000 containers. Those containers, if stacked 5 high (and not allowing for isles) would occupy almost 6 acres of prime port real estate. The storage costs can add up quickly. Plus, if you’ve got the ships there, why not use them for something?