Seamanship_Secrets_185_Tips_-_Techniques_for_Better_Navigation-_Cruise_Planning-_and_Boat_Handling_Under_Power_or_Sail_(Re)_e..

48 seamanship secrets

Invaluable Copilot: Th e Navigator’s Log

Enter anything into the log that directly or indirectly infl uences the

navigation of the vessel.

Logbooks provide a record of the past for use in the future. In a court of law,
they’re legal documents, carrying enough weight to prove your case if the need
arises. Underway, they give a clear picture of the vessel’s travels and serve the
navigator as well as any chart or publication. Indeed, for hundreds of years they
served as the only guide for navigators and ship captains because of the scarcity
of usable nautical charts.
Keep entries clear, specifi c, and easy for every crewmember to understand.
Reserve the first column for times (using the 24-hour clock time) and the
subsequent columns for true course, variation, and magnetic course. Make
columns for your distance log (or speed). Keep an open column for comments.

Sample Power Vessel Navigation Log

Time True V Mag.Dist.Log Lat. Long. Method Engine Hours Comments

1200 330 6W 336 12.5 36–42.2N 73–16.8W GPS 1,565

Wind W @ 12; Seas 2-3

1400 RPMs both Engines

1220 made visual landfall with

Pt. Judith Light

1300 330 7W 337 12.8 36–48.0N 73–18.2W Vis/Rad. 1,566

Wind WNW @ 16–18; Seas 3

1400 RPMs both engines

Sample Sailing Vessel Navigation Log

Time True V Mag.Dist.Log Lat. Long. Method Comments

1200 330 6W 336 5.5 36–42.2N 73–16.8W GPS.

Wind W @ 12; Seas 2-3

Main (full); 135 Lapper

1220 made visual landfall with

Pt. Judith Light

1300 330 7W 337 5.5 36–48.0N 73–18.2W Vis/Rad.

Wind WNW @ 16–18; Seas 3

Main (2 reefs); 135 Lapper.

Sample logbook entries for a sailboat and a powerboat.