SeaMemo
How to keep a sailing logbook
A ship's log is one of the oldest habits in sailing, and still one of the most useful. It's your proof of experience, your safety net and, years later, the best record of the trips you loved. Here's what to write in it, whether paper or an app makes more sense, and how the RYA logbook fits in.
Why keep a sailing logbook at all?
A logbook does three jobs at once:
- Proof of experience. Sea miles, sea time and night hours are what qualify you for licences and exams, from the ICC to the RYA Yachtmaster. No record, no credit.
- Safety and seamanship. Regular entries mean that if your electronics fail, you still have a recent position, course and time to fall back on, the foundation of dead reckoning.
- Memory and evidence. It's the story of your seasons afloat, and the neutral record that settles questions later, with a charter company, an insurer or your future self.
Is a sailing logbook a legal requirement?
For most private pleasure yachts there is no general legal duty to keep a logbook, but it is strongly recommended, and insurers and examiners often expect one. Commercially coded or registered vessels are a different matter and usually do have record-keeping obligations. When in doubt, keep one: the upside is large and the effort, especially with an app, is small.
What to record in a sailing logbook
A traditional log is a table with one row per entry (typically hourly on passage, or at each change of watch or course). The classic columns:
| Field | What it captures |
|---|---|
| Date & time | Local or UTC, be consistent |
| Position | Latitude/longitude or a GPS fix |
| Course | Heading steered (and COG if known) |
| Speed & log | Speed through water/over ground and the distance logged |
| Wind & weather | Wind direction and force, sea state, visibility, barometric pressure |
| Engine | Hours run, fuel, so sailing and motoring miles stay separate |
| Crew & watch | Who was on watch, changes of skipper |
| Events & notes | Sail changes, landfalls, incidents, anything worth remembering |
To judge the wind force properly, use the Beaufort scale chart and calculator.
Per passage you also record the departure and destination, the crew list and who skippered, the details that turn raw miles into a qualifying passage you can defend. For speed over ground versus through the water, and how to convert knots to mph or km/h, see knots to mph and km/h.
The RYA logbook. If you're working towards an RYA certificate, your experience lives in your own logbook (the RYA Yachtmaster Scheme Syllabus and Logbook, G158). There's no separate official form to get stamped, examiners simply question you on what you've logged. A clear, accurate, GPS-backed record is worth its weight when you're across the table from one.
Marks you pass also make good position references for an entry, for example "12:40 buoy abeam". Our guide to channel markers and buoys explains what each one means.
Paper logbook vs. a logbook app
| Paper logbook | Logbook app | |
|---|---|---|
| Recording | Manual, entry by entry | Automatic via GPS |
| Distance accuracy | Estimated or read off the log | Exact, measured over ground |
| Always with you | Stays on the boat | On your phone |
| Searchable & totalled | No | Yes, miles and hours add up on their own |
| Share with crew | Awkward | One shared trip |
| Proof / export | Copy it out by hand | Sea miles PDF for German and Austrian licences |
Paper has real charm and needs no battery, and many skippers still keep the ship's official log on board. But for building and proving your own experience, an app removes the two biggest weaknesses of paper: the manual copying and the guesswork over distance.
Which logbook apps are out there, what they cost and who they suit is in our comparison of the best sailing logbook apps. Torn between SeaMemo and SeaPeople? See SeaMemo vs SeaPeople.
A simple sailing logbook template
Starting from scratch? This is enough to keep a solid personal log:
- Trip header: boat name and type, skipper, crew list, dates.
- Per leg: from → to, departure and arrival time, distance (nm), engine hours, and whether you were skipper or crew.
- Per entry (on passage): time, position, course, speed, wind/weather, notes.
- Running totals: nautical miles, days at sea, night hours.
How SeaMemo keeps the log for you
SeaMemo fills the most important fields above on its own. Course, barometer readings or engine hours you still note yourself in the journal. Start tracking as you cast off and it logs your route, distance, speed and duration, offline, in the background, with sailing and motoring kept apart. Each leg carries its photos, weather, crew and notes; your profile keeps the running totals of miles, hours and night miles, plus who skippered. For German and Austrian licences it fills in the sea miles certificate as a PDF; for other licences you copy the figures straight into your logbook.
Get SeaMemo for free
Logbook, travel journal and crew in one app. For iPhone and Android, works offline at sea.
Frequently asked questions
Is a sailing logbook a legal requirement?
For most private pleasure yachts there's no general legal duty to keep one, though it's strongly recommended and often expected by insurers. Commercially coded or registered vessels usually do have record-keeping obligations.
What should I write in a ship's log?
Per entry: time, position, course, speed and distance logged, wind and weather, engine hours, crew on watch and any notable events. Per passage: departure and destination, crew list and who skippered.
Can I keep a sailing logbook on my phone?
Yes. A logbook app like SeaMemo records your route and distance on GPS, offline too, and adds up your miles and hours automatically, so your phone becomes a more accurate logbook than a hand-written one.
Does the RYA require a specific logbook?
You record your experience in your own logbook (the RYA Yachtmaster Scheme Syllabus and Logbook, G158). There's no separate signed form, examiners question you on what you've logged, so an accurate, detailed record matters. More on RYA sea miles →