DatumMark
IALA Buoyage
Only for iPhone
$0.99 · Designed for iPhone
iPhone
Master IALA buoyage for your RYA exam. Every mark, light, and topmark — both regions.
Quiz yourself until it sticks. Night-vision red mode for the bridge.
DatumMark — IALA Buoyage Reference & Exam Prep
Master the IALA Maritime Buoyage System with DatumMark, a comprehensive reference and revision tool for mariners, sailing students, and anyone preparing for RYA, ISA, or coastal navigation examinations.
COMPLETE IALA MARK REFERENCE
All 12 mark types of the IALA Maritime Buoyage System, covering lateral, cardinal, isolated danger, safe water, special, and emergency wreck marking buoys. Each mark includes full specifications: hull colours, shapes, topmark configurations, light characteristics, and their navigational meaning.
BOTH IALA REGIONS
Switch between Region A (Europe, Africa, Asia, Australasia) and Region B (Americas, Japan, Korea, Philippines). Lateral marks update automatically to reflect the correct colour conventions for your region. Cardinal and all other mark types are displayed identically, as per the international standard.
ANIMATED LIGHT CHARACTERISTICS
Every light rhythm is animated to IALA specification — flashing, quick, very quick, ultra quick, isophase, occulting, Morse code, long flashing, and alternating sequences. See exactly how each light behaves at night, with correct flash rates and group patterns including composite sequences like Fl(2+1) and VQ(6)+LFl.
INTERACTIVE BUOY DIAGRAMS
Rendered buoy illustrations showing accurate hull colours, horizontal and vertical banding, topmark shapes and orientations, and animated navigation lights — all drawn to IALA standard against a sky and sea background for clarity.
QUICK REFERENCE CARD
A single-screen summary of every mark — colour, topmark, and light character at a glance. Like the laminated reference card on your chart table, always in your pocket.
EXAM QUIZ MODE
Three quiz modes to test your knowledge:
Identify the Mark — recognise a buoy from its visual appearance
What Does It Mean? — match marks to their navigational meaning
Light Character — identify light rhythms from animated sequences
Ten questions per session with immediate feedback, explanations, and a pass/fail score against the RYA threshold of 7/10.
REFERENCE SECTIONS
Browse all light rhythms with descriptions and abbreviations, buoy shapes with their usage, and topmark types with the marks they belong to.
NIGHT VISION MODE
Three display themes: Amber, Green, and Red. The red theme preserves scotopic (night-adapted) vision, suitable for use on the bridge during hours of darkness.
DESIGNED FOR MARINERS
DatumMark is part of the Datum series of informational apps. Built for clarity, accuracy, and quick reference — whether you are revising for an exam, refreshing your knowledge before a passage, or settling a debate in the cockpit.
This application is provided for educational and revision purposes only. Always consult official charts, publications, and up-to-date notices to mariners.
Ratings & Reviews
This app has not received enough ratings or reviews to display an overview.
The developer, Stuart Woolley, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Provider
- Stuart Woolley
- Size
- 2.8 MB
- Category
- Reference
- Compatibility
Requires iOS 26.2 or later.
- iPhone
Requires iOS 26.2 or later. - Mac
Requires macOS 26.2 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 26.2 or later.
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © 2026 Stuart Woolley
