The Enfant Perdu lighthouse, photographed from a boat
L’Enfant Perdu is a small rocky islet off Cayenne, with the swell breaking over it. It carries a lighthouse, its solar-panel platform and the ruins of the former keepers’ buildings. Landing on it is impossible: everything that needs a close look is seen from the sky.
An inspection prepared with Cerema
In February 2024 the sea, coast and rivers directorate of DGTM scheduled a detailed inspection of two lighthouses, on Île Royale and on the Enfant Perdu. Cerema engineers carried out the visual inspection on site; for the parts they could not reach, DGTM ordered drone imagery from us on 9 February. The Île Royale lighthouse was photographed on 6 March 2024, and the photos were sorted by part of the structure: north, south, east and west faces, pillars, upper cylinder, collar and dome.
For the Enfant Perdu, access was to be by the civil protection helicopter. The mission was postponed to 2025, then scheduled for mid-November; as an agreement restricted boarding to State staff, the aircraft could not take us. The Cerema engineers made their visit in November, and the Lighthouses and Beacons unit, as project owner, then organised a trip by sea for us, with no more than three people on board the launch. Only two mornings, 8 and 9 December, suited the tides.
Taking off from a boat
On 9 December 2025 we left Le Larivot at 7 am, in the slot set by the tides; the meeting time, first set at 8.30 am, had been brought forward at the skipper’s request. We were aboard an 8 m aluminium launch fitted with a bow platform. The drone took off from this platform and returned to it on every flight, while the boat stayed off the islet.
Coverage includes vertical views of the platform, the lantern and the solar panels, and oblique views of the lighthouse and the islet. The inspection photos were delivered the same day by download link, grouped in an archive, with a separate selection of overall views for the department’s communication.
Coming back to the same structures
On an isolated lighthouse, height and access by sea complicate a conventional inspection, and rope-access teams are kept off the structure unless necessary. Drone photos give the engineers a view of every part of the structure, and a basis for comparison on later visits. On Île Royale, sorting by part of the structure makes it possible to go straight to the views of a given face or element.
