Sandettié, Museum ship at Dunkirk Port Museum, France.

Sandettié is a 47.5-metre lightship with a riveted metal hull painted red, its name in large white capitals. A red cylindrical tower with a lantern room rises toward the left, beside a red smokestack and a tall thin mast. The long, low vessel lies in Dunkirk's commercial port as part of the Port Museum's afloat collection.

Built in 1947 at the Forges et Chantiers de la Méditerranée in Graville-Le Havre as BF 6, the vessel was launched on 16 February 1948 and assigned the following year to the Dyck bank. In 1978 it was reassigned to the Sandettié bank, 13 nautical miles off Calais, and took that name. It was decommissioned on 3 June 1989 and bought by the city of Dunkirk. It has been classified as a monument historique since 17 March 1997.

The vessel demonstrates how French maritime authorities addressed the dangers of shifting sandbanks through dedicated warning systems. Visitors can observe the living and working spaces that crew members inhabited during their rotations guarding this hazardous shipping route.

The vessel is open for visitors to explore its decks and interior spaces at their own pace, allowing direct observation of the original equipment and layout. Comfortable shoes are recommended, and allow extra time to navigate the narrow stairs and tight passages typical of ships from this era.

The Sandettié was the sixth lightship to bear the name, though its own name came only from its last station. It was launched as BF 6 in 1948 and kept that number until reassignment to the Sandettié bank in 1978. Its Fresnel lens flashed white every five seconds, visible 25 nautical miles away.