Perchem

Perchem is a mooring design calculator for boat owners and yard operators who want to know, before they lay the tackle, whether the mooring will hold. Describe your berth — water depth, level range, seabed type, exposure, design wind speed, and distance to the nearest jetty. Build your mooring stack from the bed upward, choosing from twenty-two catalogued sinkers, rode items, and buoys. Perchem computes the design load on the tackle, the holding force returned by the sinker on your seabed, and the safety factor — then returns a plain verdict: HOLDS, MARGINAL, or DRAGS, with the specific margin that governs the outcome. The Holding Ground tab shows what your sinker gives back on all six seabed types side by side, so you can see at a glance what difference a better bed makes. The Swing Overlay lets you photograph the berth from the shore, mark a known reference height, and see the full tackle elevation and swing arc drawn over the photograph at true scale. When you find a fault at lift, log it against the berth — Perchem identifies the severity, records the cause, and brings the next inspection date forward automatically. Everything stays on your device. No account, no server, no sync. Perchem works fully offline, stores all berth records and fault logs locally, and exports a finished spec sheet to your photo library when the tackle is right.