Skip to main content
Black Friday: last days at $9.99. The Exam Pass goes up to $24.99 on 1 December. 17 days 09:37:37 See the Exam Pass
IALACOLREG
COLREG
Lights & ShapesSound Signals
General123
Conduct in any condition of visibility45678910
Vessels in sight of one another1112131415161718
Restricted visibility19
Lights and shapes202122232425262728293031
Sound and light signals323334353637
Exemptions38
Verification of compliance394041
IALAGMDSSExams

Pro simulators · Coming soon

Ten pro simulators. One pass.

Ten bridge and ship systems, built the way they work at sea.

See all simulatorsSee all simulators
  • Naval SimulatorBridge and ship handling
  • ECDISElectronic chart display
  • Radar / ARPARadar and target tracking
  • Chart RoomChartwork and coastal navigation
  • Celestial NavigationAstronomical navigation
  • Radio StationGMDSS radio
  • Met DeskMarine weather
  • Engine RoomMachinery and plant operation
  • Cargo StowageCargo, trim and stability
  • Fishing SonarFish finding
PassExam Pass

Language

Pass
AcademyAcademy
IALACOLREGAcademy
HomeModulesLearning pathsSimulatorsQuizzesExamsGamesLicencesThe Fleet
My activityReview mistakesCertificates

Your progress is kept on this device for now. Create a free account to keep it safe and pick it up on any device.

Save your progressBack to ialacolreg.com
Free with your accountExam Pass: unlimited mocks
IALACOLREGAcademy
Create a free account to save your progressSave your progress

My modules

Astronomy and celestial navigation

Work through the units in order, or jump to any one.

M1 COLREGM2 IALAM3 GMDSSM4 NavigationM5 MeteorologyM6 Ropes and knotsM11 Celestial navigation
Module 11 · 10 units · 10 h
0%
Coming soon. The units below show what this module will cover.
  1. 1The celestial sphere, stars and planetsLearn · 5 lessonsFreeOcean skipper30 min
  2. 23D night skySimulator · Coming soonOcean skipper15 min
  3. 3Time, the almanac and the Sun's positionLearn · 4 lessonsFreeOcean skipper25 min
  4. 4The sextant and its correctionsLearn · 5 lessonsWith the Exam PassFree previewOcean skipper30 min
  5. 5The noon sight: latitude by the SunLearn · 5 lessonsWith the Exam PassFree previewOcean skipper25 min
  6. 6Sight reduction and the position lineLearn · 5 lessonsWith the Exam PassFree previewOcean skipper30 min
  7. 7Star, planet and Moon sights; latitude by PolarisLearn · 5 lessonsWith the Exam PassFree previewOcean skipper30 min
  8. 8Compass error by azimuth and amplitudeLearn · 4 lessonsWith the Exam PassFree previewOcean skipper25 min
  9. 9Worked sights: a day's work from morning sight to noonPractise · Coming soonOcean skipper30 min
  10. 10Celestial navigation examCheck · Coming soonOcean skipper45 min
Astronomy and celestial navigationQuiz this module
IALACOLREG

A smooth sea never made a skilled sailor.

English proverb
Study
  • COLREG Rules
  • IALA Buoyage
  • Radio & Communication
  • Marine Weather
  • Navigation & Radar
  • Seamanship & Sailing
Resources
  • Exams (PER · RYA · USCG · STCW)
  • Boating licences by country
  • Lights & Shapes
  • Lights cheat sheet
  • Sound Signals
  • Glossary
  • Free lessons
  • Side-by-side comparisons
  • IALACOLREG Exam Pass
The project
  • About
  • Methodology
  • Sources
  • For schools & teachers
  • Group quiz for classes
  • Nautical Schools
  • Contact
Legal
  • Privacy
  • Terms
  • Legal notice

© 2026 IALACOLREG · All rights reserved.

hello@dockialabs.com

Developed with love by Dockia Labs

  • English
  • Bahasa Indonesia
  • Català
  • Deutsch
  • Español
  • Français
  • Hrvatski
  • Italiano
  • Nederlands
  • Norsk
  • Polski
  • Português
  • Português (Brasil)
  • Türkçe
  • Ελληνικά