ARPA · AIS · COLREG Bridge Simulator
Ship-handling and collision-avoidance practice on an integrated bridge display — radar PPI with AIS targets, realistic ARPA CPA/TCPA tracking, and type-specific manoeuvring response. 54 COLREG 72 scenarios from Rule 5 (Lookout) to Rule 19 (Restricted Visibility) and night-light recognition (Rules 23–30), plus TSS, narrow channels and multi-target situations.
Fundamentals — Rules 2, 5, 6, 7, 8
1. Familiarisation — Free Mode
Operate the radar, own-ship controls (COG & SOG) and AIS target info panel without any guided objective.
2. Rule 2 — Departure to Avoid Danger
General prudential rule: when complying with a Rule would cause immediate danger, Rule 2(b) permits departure. Resolve the dilemma.
3. Lookout — Prioritising Risks
4–6 AIS targets, randomised on every retry. Apply Rule 5 (proper lookout) and Rule 7 (CPA/TCPA) to identify which target presents the greatest risk.
4. Safe Speed in Fog
Rule 6 requires every vessel to proceed at a safe speed appropriate to prevailing conditions and traffic density.
5. CPA/TCPA Recognition
Determine whether risk of collision exists using bearing change and CPA/TCPA, per Rule 7.
6. Action to Avoid Collision
Take action in ample time, substantial enough to be readily apparent (≥ 20° turn or ≥ 4 kt speed change), resulting in passing at a safe distance.
Narrow Channels & Traffic Separation — Rules 9, 10
7. Narrow Channel — Keep Starboard
Keep as near to the outer limit on your starboard side as is safe and practicable.
8. Narrow Channel Overtaking
Overtake inside the channel — stay within channel limits, keep well clear of the overtaken vessel.
9. TSS — Joining at Shallow Angle
Join a TSS lane at as small an angle to the direction of traffic flow as practicable.
10. TSS — Cross at Right Angles
Cross a traffic separation scheme on a heading as nearly at right angles to traffic flow as practicable.
Vessels In Sight — Rules 12, 13, 14, 15, 17
11. Sailing vs Sailing
Two sailing vessels converging. Rule 12 — vessel with wind on PORT side gives way to one with wind on starboard side.
12. Overtaking
You are the overtaking vessel. Rule 13 — keep out of the way until finally past and clear.
13. Being Overtaken
A faster target is overtaking you from astern. Maintain course and speed unless safety requires action.
14. Head-On Situation
Reciprocal course. Rule 14 — both vessels alter to STARBOARD and pass port-to-port.
15. Crossing — You Are Give-Way
Target on your starboard. Substantial starboard alteration, pass astern, avoid crossing ahead.
16. Crossing — You Are Stand-On
Target on your port. Rule 17(a)(i) — keep course and speed while give-way vessel acts.
17. Stand-On — Last-Moment Action
Give-way vessel fails to act. Take action, but Rule 17(c) forbids port turn for a vessel on your own port side.
Responsibilities Between Vessels — Rule 18
18. Power-Driven vs RAM
Keep out of the way of a vessel restricted in her ability to manoeuvre (badge "R").
19. Power-Driven vs Fishing Vessel
Power-driven vessel keeps out of the way of a vessel engaged in fishing (badge "F").
20. Power-Driven vs Sailing Vessel
Power-driven vessel keeps out of the way of a sailing vessel under way (badge "S").
21. Avoid Impeding CBD Vessel
Avoid impeding the safe passage of a vessel constrained by her draught (badge "C").
Restricted Visibility — Rule 19
22. RV — Target Right Ahead
Fog. Target detected by radar right ahead, closing fast. Rule 19(d) — no alteration to port for a vessel forward of the beam.
23. RV — Target on Port Bow
Fog. Target forward of your port beam — do NOT alter to port.
24. RV — Target on Starboard Bow
Fog. Target forward of starboard beam — no alteration to port, no turn toward target.
25. RV — Target Abeam Starboard
Avoid alteration of course TOWARD a vessel abeam or abaft the beam.
26. RV — Target Abaft Port Beam
Target abaft your port beam, slowly closing. Do not turn toward it.
27. RV — Close Quarters Unavoidable
Fog signal forward of beam; close-quarters cannot be avoided by course alone. Reduce to minimum steerage way.
28. RV — Multi-Target Encounter
Two targets developing close-quarters situations simultaneously. Prioritise, apply Rule 19(d), ensure safe CPA to both.
Sound Signals — Rules 34, 35
29. Whistle Manoeuvring Signals
Power-driven vessels in sight: • = starboard; •• = port; ••• = astern propulsion. Pick the correct signal.
30. Doubt / Disagreement Signal
When uncertain the other vessel is taking sufficient action, sound the "wake-up" signal.
31. PDV Underway in Fog
Restricted visibility fog signals. Identify the correct signal for a power-driven vessel making way.
32. "— • •" Fog Signal Recognition
One prolonged followed by two short blasts — which vessel types may sound this signal?
Night Recognition — Rules 23–30 (Lights)
33. Power-Driven Underway Lights
Masthead light(s), sidelights, sternlight. Identify a vessel ≥ 50 m underway.
34. Towing Vessel Lights
Two masthead lights + sidelights + sternlight + yellow towing light. Tow length makes the difference.
35. Sailing Vessel Lights
No masthead light; sidelights + sternlight; optional red over green at mast top — "sailing machine".
36. Fishing Vessel Lights
Green over white = trawling. Red over white = other fishing (nets, lines).
37. NUC / RAM Lights
Two vertical reds = NUC. Red-white-red = RAM. Distinguish between them.
38. CBD Vessel Lights
Three all-round RED lights vertically = Constrained By Draught. Give her wide berth.
39. Pilot Vessel Lights
White over red = pilot ahead. Vessel on pilotage duty identification.
40. Anchored / Aground Lights
White anchor lights vs anchor lights + two reds = aground. Distinguish the combination.
41. PDV < 7 m AND ≤ 7 kn
Reduced lighting: single all-round white + sidelights if practicable. No masthead, no separate sternlight.
42. Anchored < 50 m — Simple
One all-round white where best seen. By day: one black ball forward.
43. Dredger / Underwater Ops
RAM lights + TWO reds (obstruction side) and TWO greens (pass side). Which side is safe?
44. Tow > 200 m
Three masthead lights vertically = length of tow exceeds 200 m. By day: a diamond shape.
45. WIG Craft (Wing-in-Ground)
PDV lights + high-intensity flashing RED all-round = WIG craft taking off / landing / in flight near the surface.
46. Hovercraft (non-displacement)
PDV lights + flashing YELLOW all-round = air-cushion craft in non-displacement mode.
47. Seaplane on the Water
Lights as close as practicable to the PDV requirement when construction prevents exact compliance.
48. Sailing Tricolour < 20 m
Combined lantern at mast top: red (port) + green (stbd) + white (stern). Allowed only for small sailers.
49. Sailing AND Motoring
By day: conical shape apex DOWN forward. By night: treated as PDV (no red-over-green).
50. Fishing — Outlying Gear > 150 m
Red-over-white + additional white all-round offset horizontally toward the gear.
51. NUC — NOT Making Way
Only two vertical reds. No sidelights, no sternlight — she is stopped in the water.
52. RAM — At Anchor
R-W-R vertically + anchor lights. No masthead, no sidelights, no sternlight.
53. Fishing — Nets / Lines
Red over white all-round = fishing other than trawling (set nets, long-lines, trolling).
54. Mineclearance Vessel
Three all-round GREEN lights (masthead + each fore-yard end) + PDV lights. Keep > 1000 m clear.