The collision, which occurred in the coastal waters of Kilindi, sent passengers into the sea in circumstances that remain under investigation.
The involvement of community members alongside professional responders reflects the urgency of the situation on the ground, where every minute counted in determining who could be reached in time.
Lamu County sits along Kenya's northern coast and is defined by its waterways.
For many residents, boats are not a leisure option but a daily necessity, used to move between islands, ferry goods, and reach mainland services that road transport cannot easily connect.
The waters around Lamu are busy, and the risk of accidents, particularly where vessels travel close together, is a reality that communities in the area live with.
Four of the 19 passengers on board the two boats sustained critical injuries, pointing to the severity of the collision.
The full circumstances of the crash, including what caused the two vessels to meet at a fatal angle, had not been officially established at the time of reporting.
Water accidents along Kenya's coast and on its inland lakes have repeatedly exposed gaps in maritime safety.
Boats operating in these waters often carry more passengers than recommended, lack adequate life-saving equipment, and travel without proper oversight.
Whether any of those factors played a role in the Kilindi incident will form part of any formal inquiry that follows.
The Kenya Red Cross, which has developed significant capacity in water rescue and emergency response, played a central role in coordinating the operation.
Its involvement alongside local divers and community members illustrates how effective emergency response in coastal areas often depends on a combination of institutional readiness and local knowledge.
Community members who know the waterways intimately can reach victims quickly in ways that outside responders sometimes cannot.
The critically injured were taken for medical attention, though details of the facilities receiving them and updates on their condition had not been released by Saturday morning.