Rubberduck – Sailing Logbook App for iPhone & iPad

Rubberduck — the digital sailing logbook · iOS App

Your voyage.
Automatically
logged.

Rubberduck records GPS track, weather, wind, NMEA data and crew details fully automatically in the background — from casting off to tying up. Plan multi-leg voyages, split costs with your crew, track maintenance, engine hours and log reading — and publish your voyages with one tap as your own ship's log on Kielwasser: with a boat profile, live position and shareable voyage cards. No paperwork, not a single manual entry.

GPS & Chart Charts Seamark Log Offline Charts NMEA 0183 Automatic Weather Anchor Watch Tidal Planner Voyage Management Cash Box Watch Schedule Packing List Safety Briefing Currency Converter Maintenance Engine & Tanks PDF Export iCloud Sync Kielwasser Web Log Live Position Shareable Voyage Cards Sound Signals 11 Languages

Languages

∞

Voyages & Photos

100%

Works Offline

Features

Everything you need
on board.

What the app does

📖

Automatic logbook

GPS track with distance in nautical miles; log entries created automatically by time interval, distance sailed or course change — each individually configurable. Runs fully in the background, your iPhone can stay in your pocket.

📡

Live NMEA data

Wind, depth, water temperature and more straight from your boat network (NMEA 0183 over WiFi) — logged automatically every 15 minutes.

🌦️

Weather, sea state & tides

48-hour forecast with strong-wind warnings, wave height, high and low water — recorded automatically at passage start and updated underway.

🧭

Voyages & legs

Voyages group legs together — with cash box (expenses, deposits, fair settlement by email), rotating watch schedule and crew management including documents.

🛠️

Ship management

Maintenance tasks with intervals and due dates, repair log with costs, spare-part inventory with stowage location, boat papers as scans.

⚓

Anchor watch

Geofence alarm if the anchor drags — with continuous GPS recording and log entries on dropping and weighing anchor.

📷

Photos & export

Passage photos with position and caption; PDF reports (summary or detailed), yearly collections, HTML export.

☁️

iCloud sync

All data — passages, photos, boat, crew, cash box, settings — automatically on all your devices. New iPhone? Everything is simply there.

🦆

Kielwasser integration

Create your ship’s log right from the app, publish passages with chart, numbers, log and photos in one tap, write posts with photos.

📣

Sharing & live position

Share cards in the Kielwasser design for Instagram stories, passage links with automatic previews for WhatsApp & co. — and if you like, your log shows live where you are sailing (🔴 opt-in, ends automatically with the passage).

🚢

Ship profile & log counter

Model, MMSI, ATIS, owner and a boat photo with your own tile crop — everything flows into your Kielwasser ship profile automatically. The ship’s log reading lives on the boat and pre-fills at passage start.

📖

Nautical references — in 11 languages

Beaufort scale, flag alphabet, navigation lights, GMDSS radio templates and audible sound signals per COLREGs (horn, bell, gong). Plus the complete manual — app, references and help in 11 languages.

⚡

NMEA 0183 — Connect your instruments directly

Connect via Wi-Fi to your NMEA gateway. Wind, depth, water temperature, pressure and heading are read directly from your instruments and saved automatically in the logbook.

TCP/IP · Auto-connect · No extra hardware needed

The right app for every sailor

Three scenarios.
One solution.

Whether you own a boat with a full NMEA setup, charter for a spontaneous holiday, or run a professional fleet — Rubberduck adapts to every situation, without compromise.

⛵

Boat Owners

Every voyage documented. Your boat, always in control.

✓Complete voyage archive with GPS track, weather and distance — runs automatically in the background, even with the screen locked

✓Group multiple legs into a voyage — see the full picture of a sailing season at a glance

✓Maintenance planner with custom intervals — never miss an oil change, impeller or rig check again

✓Repair log and spare parts inventory always at hand — even without mobile signal in the harbour

✓Built-in anchor watch with configurable radius and alarm — protects the boat overnight without needing the screen unlocked

✓iCloud Sync keeps all data up to date across iPhone and iPad — voyages, maintenance, documents and photos, all in one place

✓Your own ship's log on the web: publish voyages to Kielwasser with one tap — with a boat profile, live position for those back home and shareable voyage cards

🧳

Charter Sailors

Cast off, enjoy, settle up. Done.

✓No pen, no paper: GPS track, weather, wind and miles sailed are recorded fully automatically — from the very first metre

✓The Cash Box splits shared costs fairly among the crew — fuel, marina fees, provisions — and calculates the final settlement automatically

✓Never forget the packing list: start from ready-made categories or build your own — synced via iCloud to every crew member's device

✓Plan night watches with the built-in Watch Schedule — fair shifts, clearly assigned, synced to every crew member's device

✓Tidal data is detected automatically for the nearest station via GPS and logged during the voyage — especially useful in the North Sea and along Atlantic coasts

✓Currency converter with live rates for 30+ currencies — available offline too, ideal for sailing abroad

✓At trip end, generate a complete logbook PDF with one tap — as a keepsake or to hand back to the charter company

✓11 languages supported — ideal for international crews where not everyone speaks the same language

🏢

Charter Companies & Yacht Clubs

More safety. Delighted guests. Your fleet, always documented.

✓Uninterrupted GPS track of all voyages with weather and logbook — clear, timestamped documentation for damage claims, groundings or insurance cases

✓Conduct safety briefings in a structured and documented way — guests confirm with a signature, record saved with date and participants

✓Maintenance planner and repair log per boat — transparent service history for every vessel in the fleet

✓Document engine hours and tank levels at every handover — boat condition recorded at start and end, no disputes

✓Store boat documents and crew certificates digitally — accessible offline, no paper folders needed on board

✓Guests can publish their trip reports with chart and photos to Kielwasser or your own website — real content, no effort from you

✓iCloud Sync gives an overview of the entire fleet across all devices — voyage history, maintenance status and tank levels always current

Create a voyage & select crewName, start date, participants

Start a leg — one tapGPS, weather and NMEA run automatically

Sail & enjoyEverything logged silently in the background

End leg, start the nextOr end the voyage back in port

DonePDF ready, costs settled

iOS App

Now on the App Store.

For iPhone & iPad · iOS 17+

Scan to download

Sailing on the Ijsselmeer and the North Sea

sy rubberduck

Our Passages

Your voyage.
Automatically
logged.

NMEA 0183 — Connect your instruments directly

Sailing on the Ijsselmeer and the North Sea

sy rubberduck

Our Passages

Your voyage.Automaticallylogged.

NMEA 0183 — Connect your instruments directly

Your voyage.
Automatically
logged.