Why are lightships useful where a permanent lighthouse cannot be built?

Lightships serve as essential marine navigation beacons in locations where constructing a permanent lighthouse is impractical or too costly.12

Their primary utility stems from several key factors:

• Mobility: Unlike fixed structures, lightships can be easily redeployed to mark shifting hazards, such as moving sandbanks, or to adjust to changing traffic patterns in coastal waters and harbor approaches.13
• Versatility: They provide a platform for powerful aids to navigation, including fog signals and radio beacons, in areas where seabed structures are not feasible.12
• Adaptability: Because they are floating, they can be moved to accommodate the needs of deep-draft vessels requiring safe passage through evolving channels.3

While historically significant, many lightships were eventually replaced by automatic buoys due to the high costs associated with their operation and maintenance.2