Why Lighthouses Matter: Navigation, Warning, Heritage, Science

1. Navigational Aid

• Fix position via bearing/range; confirm landfall.
• Daymarks (tower color/pattern) + light signatures (flash period, color).
• Visible 15–25 nm (nautical miles) depending on height/power.

2. Hazard Warning

• Mark rocks, shoals, reefs, wrecks, channel edges.
• Sector lights: colored arcs show safe/danger zones.

3. Landmark & Position Fixing

• Recognizable coastal reference points.
• Cross-bearing with two lights = precise fix (pre-GPS; still backup).

4. Historical & Cultural Value

• Engineering feats (Eddystone, Bell Rock, Skerryvore).
• Community identity, tourism, heritage designation.
• Keepers' lives: isolation, duty, rescue lore.

5. Emergency & Communication

• Some equipped as rescue shelters, radio relays, AIS base stations.
• Weather/sea-state reporting (synoptic network).

6. Scientific Platforms

• Meteorological/climate sensors (long-term records).
• Seabird/bat monitoring, migration studies.
• Oceanographic: wave, current, temperature loggers.

Even with GPS, lighthouses remain critical redundant aids and irreplaceable cultural assets.