a quick overview:
https://velahelm.com

Velahelm turns your Android phone/tablet into a high-performance sailing cockpit. It doesn’t just repeat instrument numbers — it verifies, derives and explains them (even offline), so you can make faster, safer decisions while cruising or racing.

⛵ Live data + smart math
• NMEA 0183 via UDP, TCP or TCP server (checksum verified)
• Automatic fallback to device GPS/time when NMEA drops out
• Derived metrics when your network is incomplete:
True/ground wind (TWS/TWD, GWS/GWD), set & drift, VMG/VMC/CMG, heading-to-steer, optimum tack/gybe angles and more

🏁 Racing / Start tools
• Start sequence & countdown
• Start-line view (boat + pin), distance & time-to-line
• Bow-offset compensation for accurate line calls

📈 Polar performance engine
• Import/edit polar tables on-device
• Target speed & performance % (PPC) in real time
• Optimal VMG/CMG courses with gain indicators

🧭 Navigation, waypoints & events
• Local waypoint manager (add/edit, filter, “near me”)
• Store incoming NMEA waypoints locally (optional)
• Great-circle or rhumb-line course-to-waypoint + TTG / XTE
• Regattas & trips: manage events/courses and share as .vhpack

🖥️ Dashboard made for cockpits
• Fully customizable grid and tile layouts (phones → large tablets)
• Presets (save/load), reorder mode, fullscreen + touch-lock, keep screen on
• Units & formats (kn/kmh/mps, ° formats), smoothing/damping
• Advanced tiles: wind trend graphs, Dir+Speed split, TWS/GWS graphs, mean direction, points, ghost line

🔔 Intelligent alarms
• Condition-aware alarms for any metric (threshold + hysteresis, moving-only, night-only, etc.)
• Visual / sound / vibration cues
• Optional background monitoring

📡 Hardware integrations
• Calypso Ultrasonic wind sensor via BLE - optionally acting as Calypso Gateway
• Remote Display Sync: pair via QR and push your dashboard/layout to another Android device
• Garmin “Velapace” link: send key data to compatible watches and configure watch layouts/backgrounds

Everything runs locally for speed and reliability.

⚠️ Navigation notice
Velahelm is an aid to navigation and performance optimization, not a certified navigation system. Always cross-check with approved instruments and keep proper lookout.

more info:
https://www.velahelm.com/en/