Complete guide to logbook and its entries on Merchant vessels


Ship’s Logbook is a very important document that reveals actual details on board the ship which includes, meteorological observations, emergency drills, education and training, incidents, accidents, winds, course, distance, positions of the vessel (bearing and distance or Lat/ Long) especially at noon, course alteration, rpm, barometer, dry and wet temperature, sounding of ballast tanks, fresh water and drinking water Remaining On Board (ROB) and consumption, Fuel Oil (FO), Diesel Oil (DO), Lube Oil (LO) Remaining On Board (ROB) and consumption, etc.

The ship’s (Deck) logbook must be kept on the bridge and the chief engineer’s logbook in the engine room and must be retained on board a ship for a specified period as per companies SMS.


Entries in the logbook need a lot of short terms like E.O.S.P or C.O.S.P that you must know.

  • SOP and EOP Start of Ocean Passage (SOP) time given after the pilot has disembarked and when the captain decided to put the engine to rung-up.
  • End of Ocean Passage (EOP) is the time given when the vessel has reached the destination point and standby the engine to pick-up the pilot, anchoring, and drifting
  • Comencement of sea passage (COSP)
  • Voyage Number The voyage number and the timing of its changeover must be in accordance with the instructions of the ship’s charterer

Units to Use and Number of Digits

a) Distance run must be in nautical miles rounded to the nearest whole number.

b) Bearings and angles (course, errors, etc.) must be in the 360 degrees system in whole numbers.

c) Temperature must be in centigrade rounded to one decimal place. (For entries in the engine log, round the figure to an integral number or the first decimal place.

d) Atmospheric pressure must be in hPa rounded to one decimal place.

e) Wind direction must be true wind direction and expressed by the 16 compass points.

f) Wind force must be in the Beaufort scale.

g) The degree of visibility must be according to the table of visibility.

h) Tides, etc. must be in meters units rounded to one decimal place.

i) Ship’s position must be in units of minutes.

j) The distance from a landmark when indicating an anchored position must be in meters units.

k) Slip % must be rounded to one decimal place.

l) Engine speed must be in r.p.m. to one decimal place.

m) Weights of fuel oil, freshwater, drinking water, cargo, etc. must be in M/T rounded to one decimal place.

n) Draught must be in meters to the second decimal place.

o) Quantity of lubricating oil must be in whole number of liters.

p) Flowmeters must be read directly.


a) Hourly distance run (log and over the ground).

b) Time difference made from G.M.T.

c) Course charted by gyrocompass (I. Co.).

d) Hours underway, hours propelling, distance run (log and over the ground), average speed (log and over the ground), amount of FO used (port departure to port entry), revolution per minute (RPM) for main engine, slip, current set and drift from noon to noon.

e) We Mention distance to go, Log distance, Avg speed of that hour, Heading (Both compass and gyro), Position (Latitude and Longitude)- is logged hourly.

f) Anchor position (direction and distance from a conspicuous object).

g) Name of port, berth, number, and time for noting drafts fore and aft (when entering port and while berthing, note drafts at 0800 and 1700. Entry for drafts noted when entering or leaving port must be made in red.)

h) Change of command from the Captain to the duty officer and vice versa, and the times.

i) Setting and changing the “Watch Level” with the times

j) Time when course was altered, and the position and reading of the log at that time.

k) Time when prominent landmark was passed, and the bearing, distance and reading of the log.

l) Conditions of sea surface and swell waves every four hours (use terminology to describe the length and height of swell).

m) Time when departure point was determined, and the bearing and distance to a prominent landmark.

n) Work and time regarding entering and leaving harbor (when anchored, the anchors used, length of anchor chain, and depth of water).

o) Status of use of main engine (S/B time, adjustment of revolution per minute (RPM) during passage, etc.).

p) Times when major navigational aids, breakwaters, etc. were passed when entering and leaving the harbor.

q) Full name of the pilot, and times and places where he embarked and disembarked.

r) Time when tugboat was used, how used, and name of the tugboat.

s) When passing through a canal, etc., the time when each lock was entered and left, the ship number when grouped into a fleet, the time and number of canal personnel who boarded and left the ship.

t) Start/stop of the UMS operation/watchkeeping of the engine department and the times.

Cargo operation work and Inspection

a) Timings when cargo work was started, suspended, and finished, number of gangs, etc., and times and quantities of loading and discharging of mail cargo.

b) N/R tender, hose connection, ballasting, etc. by specialized vessels, etc.

c) Times and quantities of replenishment of fuel, freshwater, and drinking water.

d) Nature and time of shipboard deck department work. Details of various shipboard checks, inspections, and drills. (Entries of drills to be underlined in red ink).

e) Details of any ships in distress that are learned of during passage (excluding those learned of by radio).

f) Results of inspection tour of ship after watch is over and of machinery spaces at night.

g) Details of surveys by flag state or classification society.

h) Details of inspection of Port State Control (PSC), Flag State, Oil Major etc.

Matters to be observed when making Entries in Logbook

a) Clerical errors and mistakes in entries, etc. must be corrected by drawing two black lines through the error, and after being rewritten, must be signed by the person making the entry. Under no circumstances are the errors to be blanked out, erased, cut out or pasted over, or the sheet discarded.

b) Make the entries in carefully written and legible letters.

c) Do not soil the sheets.

d) Make the entries in black ink or with a ballpoint pen. (Pencils must not be used and, in the case of the ship’s log, pencil drafts are also not allowed).

e) Port arrival and departure time entries must be written in red and framed with a parallelogram.

f) Entries of the starting and closing times of going under steam must be written in red and bracketed.

g) Entries on changing to the next voyage number and on a change in Captain or chief engineer must be entered in blacked and underlined in red.

h) Entries of the classified totals of the outward voyage, homeward voyage, and one voyage in the ship’s log must be made with a red ballpoint pen and those of the chief engineer’s log must be made on the form specified for each ship and attached.

i) The ship’s log must be entered without delay after the watch is relieved and the chief engineer’s log must be entered by the time fixed for the day or by the date and time instructed by the chief engineer.

j) Entries must be in English.

k) In the chief engineer’s log, entries on the amounts of fuel oil, lubricating oil, boiler water, freshwater, etc. consumed and hourly entries, etc. must be demarcated with a black line when changing from sailing to berthing and with a red line when changing to the next voyage no.

l) The Captain and the chief engineer must always examine and sign the entries on that day.