SW-INC-0260

La Mangue Bleue - Catamaran's hulls split at sea off Mayotte; two crew drift eleven days before rescue

The connecting beam of the cruising catamaran La Mangue Bleue failed and the two hulls separated on passage to Madagascar; two of the four aboard were found alive after eleven days adrift near Nosy Bé.

verified · 1 sourceN
Vessel
La Mangue BleueCruising catamaran
When
2016Indian Ocean
Crew
4 aboardAll survived
Outcome
Rescued
Position
Mozambique Channel between Mayotte and Madagascar; survivors found near Nosy Bé, Madagascar
Sea area
Mozambique Channel · Mayotte–Madagascar
Coordinates
-13.00°S, 47.00°EApproximate position
Summary

What happened.

On 9 July 2016 the cruising catamaran La Mangue Bleue left Mayotte for Madagascar with four aboard. At sea its two hulls separated when the bolted cross-beam connecting them failed — all 126 bolts had worked loose — and the boat broke apart. Two crew were rescued quickly by fishermen; two more drifted on a piece of hull for eleven days and 222 km before being found alive near Nosy Bé on 21 July. All four survived.

On Saturday 9 July 2016, the cruising catamaran La Mangue Bleue set out from Mayotte for Madagascar with four people aboard. Somewhere at sea, the structure that held the boat together gave way: the bolted connecting arm — the cross-beam linking the two hulls — failed when all 126 of its bolts worked loose, despite thread-locking compound and the crew's attempts to keep them tightened. The catamaran broke in two. Two of the four aboard were rescued relatively quickly by fishermen. The other two were not so lucky: clinging to a section of the broken hull, they drifted for eleven days and more than 222 kilometres across the Mozambique Channel before they were finally spotted and found alive, about ten nautical miles from the island of Nosy Bé off Madagascar, on Thursday 21 July 2016. Remarkably, all four survived. The cause was not weather or a reef but the slow, invisible failure of the fasteners holding a multihull together — a sobering reminder that on a catamaran, the structure itself is a safety system that has to be inspected and maintained.

ConditionsThe cruising catamaran La Mangue Bleue left Mayotte on Saturday 9 July 2016, bound for Madagascar with four people aboard. At sea, its two hulls separated: the bolted connecting arm (cross-beam) between them failed when all 126 of its bolts worked loose, despite thread-locking compound and the crew's efforts to keep them tight. The catamaran broke apart. Two of the four were rescued relatively quickly by fishermen, while two men clinging to a section of hull drifted for eleven days and more than 222 kilometres before being found alive about 10 nautical miles from the island of Nosy Bé, off Madagascar, on Thursday 21 July 2016. All four survived.
SeaWise noteA multihull's great strength — two hulls joined by a beam — is also a single point of failure, and here it failed quietly: 126 bolts backing out over time, not a dramatic wave. Loctite is not inspection. Know your structural fasteners, check them on a schedule, and watch for movement, weeping or cracks at the beam. If the worst comes, these survivors' lesson is stark: stay with the wreckage — it kept two of them alive for eleven days.
Lessons learned

What it teaches.

  • 1
    On a multihull, the structure is a safety system — inspect it. La Mangue Bleue broke up when all 126 bolts of the cross-beam joining her hulls worked loose. Thread-lock is not a substitute for inspection: check the torque and security of structural fasteners on a schedule, and watch for movement, weeping, fretting or gelcoat cracks around the beams.
  • 2
    Stay with the wreckage. Two of these four survived eleven days because they clung to a section of hull — floating debris is buoyancy, shelter and a far larger target for searchers than a swimmer. Unless it is dragging you down, hold onto the biggest piece that floats and make yourself as visible as you can.
  • 3
    Prepare to survive days, not hours, adrift. A drift of eleven days is extreme but real. Keep a grab-bag you can reach instantly with water, a means to collect more, sun protection and signalling gear — and above all a registered EPIRB or PLB, so the search is measured in hours, not the eleven days these two endured.
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Record IDSW-INC-0260
Curated bySeaWise editorial
Confidenceverified · 1 source
Record typeIncident

About SeaWise records: We catalogue sailing emergencies with structured metadata and link to primary sources rather than republishing them. Individual crew names are anonymised by default— sources we link to may name them publicly; SeaWise refers to roles ("the skipper", "the crew") on our pages. Submitter identities are always private.