Graduated shark-response — perimeter + drone relay

The core of this system is the module network. Five modules close a rectangular swim zone (3 seaward + 2 flanks), with the detection tiers out at sea so the shark is caught before entering. On their own — without any drone — the modules detect, classify and locate the shark by triangulation, deter it with graduated acoustics and then an electric boundary, and show its direction through their lights (red on the nearest, green on the rest). This already works satisfactorily.

Two drones are optional. They are driven by the module network — the system already knows the shark’s position by triangulation before any drone is sent. The underwater drone (pale blue), cable-docked on a module, is steered by that triangulated position to interpose ahead of the shark — between it and the swim zone — backing up with aggressive pings to deter it earlier and further offshore. It trails a red surface ball; if the lifeguard chooses, the aerial drone flies out to find that ball and, from it, pinpoints the shark’s position and heading more precisely — something the module lights already convey, to a lesser degree. Their benefit is faster confirmation (a few seconds) and earlier deterrence, not the system’s foundation. Use Continue / Back (or ←/→).

The module network is the core system: five modules close a rectangular swim zone, detect, classify, locate the shark by triangulation, deter it with graduated acoustics and an electric boundary, and show its direction by light colour — all without any drone. Two optional drones, driven by the modules, add faster confirmation and earlier deterrence: an underwater drone, steered by the triangulated position, interposes ahead of the shark and trails a red surface marker; an optional aerial drone finds that marker to pinpoint the shark visually.