In short
A ship's log belongs to the vessel; a personal logbook belongs to the sailor. Schools and charter bases want the second.
A passage entry holds the date, the boat, the ports, times of departure and arrival, distance run, engine hours, weather, crew and your role.
Role matters more than distance: the same passage counts differently for a skipper, a watch leader and a deckhand.
Miles are the distance actually sailed, not the straight line between ports. Beating to windward counts.
A GPS track beats memory: dated, tied to the ground and still readable years later.
Logbooks come on paper and on screen. Keep both: one counts, the other carries the signatures.
What a logbook is
The word covers two different things, and which one you are being asked for changes everything.
The ship's log belongs to a particular vessel: watch changes, courses and positions, instrument readings, engine work, incidents, arrivals and departures. Sell the boat and the log goes with her.
The personal logbook is your own, and it accumulates your experience. It moves from boat to boat with you, and it is what a school, an examiner or a charter base wants when they ask what you have actually sailed.
Is a ship's log compulsory?
On vessels under classification society survey, keeping a log is a requirement. On a small pleasure craft there is usually no such obligation, and the log is kept by choice. The rules depend on the flag, the type of vessel and the nature of the voyage, so in a doubtful case check your own country's requirements and your insurer's.
A personal logbook is compulsory nowhere. Without one you simply cannot prove experience — and so cannot move up to the next certificate.
What to record on a passage
The minimum that gets asked for later:
Date — one line per passage.
Vessel: name, type and length. A monohull, a catamaran and a motor cruiser are different experience.
From and to: ports of departure and arrival, or the sea area if the passage was a round trip.
Times of departure and arrival with the time zone. On long passages UTC is easier.
Distance run in nautical miles.
Engine hours, kept separate from miles. Miles under sail and under power count differently in different schemes.
Role: skipper, watch leader or crew. The most valuable field in the book.
Crew: how many aboard and who was in command.
Weather: wind direction and force, sea state, visibility. Not decoration — this is where a school reads whether you have sailed in anything fresh.
Night hours under way, if there were any.
What happened: reefing, gear failure, a dragging anchor, assistance given, running for shelter. One line turns a column of figures into a history.
A passage of several days is normally split by day, which keeps days at sea and night watches easy to total.
Why a track beats memory
Remembered distances are never right. A month on, Pula to Rovinj becomes "about thirty miles", when you spent half the day beating and covered fifty.
A GPS track settles it. It records the path actually sailed rather than the straight line between ports, it timestamps each leg, and it stays tied to a date and a place. Two years later it can still tell you the route, the conditions and where you sat for four hours waiting for wind.
The track is useful long before then. It shows where you pointed higher than you thought, where the tide set you down and which tack the boat likes. That is not paperwork — that is learning.
How miles are counted
A nautical mile is 1852 metres. Every certificate requirement is written in them.
What counts is the distance actually covered. If the rhumb line between two ports is 20 miles and you sailed 35 getting there, 35 goes in the book. Those miles were genuinely sailed.
What generally does not count: time at anchor and alongside, days without going to sea, and passages on which you were a passenger taking no part in running the boat. Every organisation words this its own way. IYT, for example, defines "at sea" as being outside any harbour where a cruising yacht could lie for a prolonged period, and counts a day at sea differently by level — eight hours under way for some certificates, twenty-four consecutive hours for others. Always take the definition from your own body.
Hence a simple rule: record the facts, not your interpretation of them. Distance, time, role. How that maps onto a particular certificate can be worked out later.
Accuracy and signatures
Fill the book in on the day. Not on Monday evening for the whole week: the details go first, and it is the details that make an entry convincing.
Do not round up. An inflated mileage falls apart at the examiner's first "tell me about this passage": someone who has sailed 400 miles remembers them, someone who wrote them in does not.
A skipper's signature or a school's stamp is what turns your line into evidence. Ask for it there and then, aboard, while everyone is still around. And note the skipper's contact details: confirmation may be wanted years later, by which time the phone number will have vanished.
Paper and electronic
A paper logbook is the ruled little book carried by chandlers and schools. It is still asked for, and not out of nostalgia: paper has room for a signature and a stamp, which an electronic entry on its own does not give you.
An electronic logbook is an app or a spreadsheet. It totals the miles itself, does not get wet, does not disappear with a lost bag, and adds up a season in a second.
The sensible arrangement is both. The electronic one is the source of data — tracks, distances, times, engine hours. The paper one carries the signatures and stamps. When the time comes to apply for the next rung, you copy figures across instead of trying to remember a June two years ago.
The logbook in the app
In Voone the logbook is built around recording as you go, not filling in a table afterwards.
A passage starts with the round Record button in the bottom bar. Before setting off you choose the mode — under sail or under power — the boat from "My boats", and the "from" and "to" points; the starting place comes from your position. After that the app counts: time, miles, speed, track points. Recording continues in the background, so the screen can be locked. The mode switches under way and the passage remembers both legs — engine hours accrue only on the powered one.
At the finish come the totals and a note field. The note is the place for what has no field of its own: your role, who was aboard, who was in command, what happened on the way.
The passage card then shows the track on a map — green at the start, red at the finish — the miles, time under way, average and maximum speed, plus charts of speed, wind and wave that highlight the matching leg. The track exports as GPX.
The logbook itself totals the season: passages, miles, engine hours. The list filters by boat, and each boat — your own, chartered or club — keeps its own history. Tracks live on the device and need no connection.
Frequently asked questions
How do I fill in a sailing logbook?
One line per passage, on the day. Date, boat, ports, times of departure and arrival, miles run, engine hours, weather, crew and your role, plus a line for anything out of the ordinary. Then the skipper's signature or the school's stamp.
How does a ship's log differ from a personal logbook?
A ship's log is kept for the vessel and stays with her. A personal logbook is kept for you and stays with you. Certificates need the second, and the two should not be confused.
How do I record a yacht track by GPS?
With any app that logs position in the background. In Voone that is the round record button: track, miles, time and speed are counted automatically, screen locked or not, and the track exports to GPX.
Do miles under engine count?
Usually yes, though schemes differ and miles under sail often carry more weight. That is why engine hours are recorded separately — so nothing has to be reconstructed later. Check the rules with your own organisation.
Do I still need a paper logbook if I have an app?
As a carrier of signatures, often yes. An app counts better and forgets nothing, but a skipper's signature and a school's stamp still live on paper. Let the app be the source of figures and the paper the place for confirmations.
How do I get miles without a boat of my own?
Deliveries, races, coastal passages, outings with friends and club training. The point is to record every trip straight away and ask for the signature on the spot. There is a separate article on that.
What next
Start with two screens. Logbook collects every passage and the season totals; My boats holds the vessels you sail, chartered ones included, from before the handover. After that it is a matter of pressing the round record button on every trip, however short: totalling miles from entries is easy, recovering them from memory is not.
How recording and reading a passage work is set out in "Recording a passage" and "Reading a passage: map, charts, GPX", and the boat card in "My boats".
Once the miles gather you will want the thresholds: how many the next rung needs and who signs the entries off. That is "Sea miles for a certificate: how many and how to get them". If you are still choosing which document to go for, start with "Yacht licences: GIMS, IYT, ISSA and RYA — which one to get".
Passages and miles also show up under Progress, alongside test results in one picture of how preparation is going.