A digital ship's logbook: what to record and how to keep it on your iPhone
By Luis Carvajal · Updated 1 October 2026
In short: a good logbook records where from and where to, when, which way and what happened. Kept digitally, the tedious part —position, miles, hours— writes itself, and you only note what matters. And it is better kept on your phone than in someone else's cloud.
What to record
For a recreational boat the logbook is above all your own record: for remembering, for learning from every trip and for keeping a history of the boat. The basics of each passage:
- Departure and arrival: harbour or anchorage, and time.
- Track: which way you went, miles and hours under way.
- Weather: wind, sea state and the forecast at the time.
- Crew and who was at the helm.
- Events: breakdowns, changes of plan, where you anchored and how the anchor held.
- Maintenance: engine hours, fuel, things to check.
If your boat or activity requires a specific official log, check the rules that apply to you: here we talk about the logbook as the skipper's personal record.
Paper, app or "online logbook"
Paper never runs out of battery, but nobody writes down the position every hour on a summer passage. An app records the track by itself and lets you add notes one-handed. The important question is where it is stored:
- In an online account: you can reach it from anywhere, but your passages live on someone else's server, and if the service closes or changes its terms, it affects you.
- On your phone: no account, no sign-up, no dependency. In exchange, you need to remember backups.
How Offing does it
Offing writes the log while you sail. Each passage is kept whole: the track drawn on the chart, the miles, the hours and from which harbour to which.
- Log entries, each with its time and position, without looking them up.
- The day's photos inside the passage.
- Logbook as PDF by period —this month, this year or everything— to keep, print or send.
- Passages as GPX, to take them to another app or your computer. You can import them too.
- No account: your passages stay on your iPhone. Offing keeps a copy inside the app that is included in your iPhone backup, and lets you save another outside it, to iCloud Drive or your computer.
- From the Apple Watch you start and stop the passage without taking your phone out of your pocket.
The PDF says it in its footer: the tracks record what was sailed; they are not a nautical chart.
Frequently asked questions
Is the passage recorded with no signal?
Yes. The passage is recorded on the phone with or without a network, airplane mode included. See Sailing with no signal.
What if I lose my phone?
If you have an iPhone backup, the logbook comes back by itself when you restore the new phone: passages, entries and photos. If you delete the app, though, iOS removes its internal copy; that is why Offing reminds you to save a copy outside the phone.
Can I move my passages to another app?
Yes, as GPX, the format almost all navigation software understands.
Offing
A logbook that writes itself, with photos and entries, as PDF whenever you like. Mediterranean chart, the official forecast, iPhone and Apple Watch, no account, one payment.
