Calculate tackle holding power, visualize swing arcs, track faults — all offline from your berth
No account required • Zero server dependency • Full local storage
Access professional-grade berth analysis features immediately after installation
All features included in Perchem 2.0 download. No subscription fees. Fully functional offline without internet connection.
How Perchem computes whether your tackle will hold before you lay the first component
Perchem runs complete mooring calculations locally on your device using cataloged tackle components. Input your berth parameters including water depth, level range, seabed classification, exposure angle, and design wind speed. The app computes design load through wind-on-hull physics and compares it against the holding force your chosen sinker returns on the specified seabed type.
The safety factor calculation divides holding capacity by imposed load to deliver one of three verdicts: HOLDS when the margin exceeds safe thresholds, MARGINAL when conditions approach limits, or DRAGS when tackle is insufficient. Orange load values display in Newtons while holding force appears in kilonewtons, with blue reserve percentage showing your safety margin.
Every berth record stores tackle gauge measurements, mass-to-water calculations, head rope ratios, and component schedules listing each element from sinker to surface buoy. Swing arc visualization overlays your boat's movement envelope at true scale onto photographs captured through your device camera, showing tackle elevation relative to jetty height and high water bands.
Professional mooring design tools purpose-built for boat owners and yard operators
Calculate real-time safety margins with HOLDS, MARGINAL, or DRAGS verdicts based on design load versus holding force returned by your sinker on the specified seabed.
Design mooring assemblies from 22+ cataloged items including mushroom domes, banded spheres, spliced thimble eyes, chain links, shackles, and swivels with accurate mass specifications.
Compare holding ground performance across soft mud, soft clay, fine clay, weed-over substrates, and two additional bottom types to optimize sinker selection.
Overlay boat movement envelope at true scale on device photographs showing tackle elevation, water bands at high tide, and freeboard relative to jetty deck height.
Track nine inspection fault types including chafed rope strops, wasted chain links, seized swivels, pitted shackles, cracked concrete blocks, and waterlogged floats with severity tagging.
Generate complete tackle specification sheets with safety factors, component lists, and berth parameters, exporting directly to your photo library for documentation.
Understanding Perchem's calculation methodology and inspection workflow
Perchem is developed by maritime engineering specialists focused on mooring safety for recreational and commercial boat operations. Version 2.0 introduces assorted improvements and fixes to the core calculation engine, with continued emphasis on offline functionality and zero-dependency architecture. The app stores all berth records, tackle configurations, and fault logs exclusively on your device with no server synchronization or account requirement. Perchem operates as a professional utility tool for yard operators managing multiple berths and boat owners designing permanent mooring installations.
iOS 12.0 or later • 100% offline operation • Free download with complete feature set • Average install time under 60 seconds
Download PerchemRequires iOS 12.0 or later. No subscription fees. No advertisements. Rated for all ages. Complete privacy with local-only storage.