All COLREG & VHF Practice Scenarios

70 browser-based maritime training drills covering the COLREG 1972 collision-avoidance rules and VHF Short Range Certificate radio procedure. Ideal for RYA and Yachtmaster prep, deck-officer cadets and skippers refreshing certification.

📜 55 COLREG 📡 15 VHF SRC ✓ 12 free demos 🌐 No install

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ARPA · AIS · COLREG Bridge Simulator 55 scenarios

Bridge-style ARPA radar with AIS overlay. Practise CPA/TCPA assessment, give-way / stand-on action, restricted visibility, narrow channels, TSS, sound signals and night-light recognition.

FUNDAMENTALS — RULES 2, 5, 6, 7, 8

EXPLORE

Familiarisation — Free Mode

Busy-traffic familiarisation on an INTEGRATED BRIDGE display AIS targets overlaid on a radar-style PPI. This mirrors a modern ECDIS/radar where the two data …

RULE 7

CPA/TCPA Recognition (Rule 7)

A single target is inbound. Under Rule 7 you must use all available means (radar, AIS) to determine if risk of collision exists. Observe the target for at le…

RULE 6

Safe Speed in Fog (Rule 6)

Visibility is under 1 NM and AIS shows dense traffic. Rule 6 requires every vessel to proceed at a SAFE SPEED appropriate to prevailing conditions. Rule 19(b…

RULE 8

Action to Avoid Collision (Rule 8)

Clear visibility. A power-driven vessel is inbound on a fine starboard bow, on a collision course. Apply Rule 8 — and alter to STARBOARD (Rules 14 / 15: neve…

RULE 5

Look-Out Scan & Identify (Rule 5)

Conduct a proper look-out by sight and hearing. Identify all targets in the vicinity by name and bearing. Rule 5 requires every vessel to maintain a proper l…

DEPARTURE FROM THE RULES — RULE 2

RULE 2(A)

Rule 2 — Departure to Avoid Immediate Danger

DILEMMA: Clear visibility. You are the STAND-ON vessel in a crossing situation a power-driven give-way vessel is on your PORT side and has failed to act. Rul…

RULE 23(A)

Rule 23 — Power-Driven Vessel Underway Lights

NIGHT. You observe the following lights approaching from ahead: two MASTHEAD lights on separate masts (the forward one lower, the after one higher); RED side…

RULE 24(A)

Rule 24 — Towing Vessel Lights

NIGHT. A vessel carries: TWO masthead lights in a vertical line (forward mast); red & green sidelights; a white stern light + a YELLOW "towing light" directl…

RULE 25(A)

Rule 25 — Sailing Vessel Underway Lights

NIGHT. You see an approaching vessel showing: red & green sidelights (she is heading toward you); NO masthead light at all. Optionally: two all-round lights …

RULE 26(B)

Rule 26 — Fishing Vessel Lights

NIGHT. A vessel in your vicinity shows at or near her masthead two all-round lights: GREEN OVER WHITE, in a vertical line. She is making way. What is she doing?

RULE 27(A)

Rule 27 — NUC / RAM Lights

NIGHT. You observe a vessel showing at her masthead THREE all-round lights in a vertical line: RED WHITE RED. She is making way through the water and also sh…

RULE 28

Rule 28 — CBD Vessel Lights

NIGHT. A vessel shows THREE all-round RED lights in a vertical line in addition to the lights required for a power-driven vessel. What is she?

RULE 29(A)

Rule 29 — Pilot Vessel Lights

NIGHT. You observe a vessel showing at or near her masthead two all-round lights in a vertical line: WHITE OVER RED. She also shows sidelights and a sternlig…

RULE 23(D)

Rule 23(d) — PDV < 7 m AND ≤ 7 kn

NIGHT. A very small power-driven vessel is observed. Her length is less than 7 m and her maximum speed does not exceed 7 kn. She exhibits ONE all-round WHITE…

RULE 27(D)

Rule 27(d) — Dredger / Underwater Ops

NIGHT. A vessel is engaged in dredging or underwater operations. She shows: the three RAM lights vertically (RED-WHITE-RED); she is working on station, NOT m…

RULE 24(A)

Rule 24(a)(i) — Tow > 200 m

NIGHT. A towing vessel shows: THREE masthead lights in a vertical line on the forward mast; sidelights; sternlight; YELLOW towing light above the sternlight.…

RULE 23(B)

Rule 23(c) — WIG Craft (Wing-in-Ground)

NIGHT. A sleek low-flying craft with stubby wings skims just above the surface. She shows normal PDV lights (masthead + sidelights + sternlight) AND an addit…

RULE 23(B)

Rule 23(b) — Air-Cushion Vessel (Hovercraft)

NIGHT. A wide low craft skims across the surface on an inflated skirt, leaving no wake. She shows normal PDV lights (masthead + sidelights + sternlight) AND …

RULE 27(A)(I)

Rule 27(a) — NUC NOT Making Way

NIGHT. A vessel shows TWO all-round RED lights in a vertical line where they can best be seen, and NOTHING ELSE no sidelights, no sternlight, no masthead lig…

RULE 27(B)(I)

Rule 27(b) — RAM At Anchor

NIGHT. A vessel shows three all-round lights in a vertical line where they can best be seen: RED-WHITE-RED. She shows NO masthead light, NO sidelights, and N…

RULE 26(C)(I)

Rule 26(c) — Fishing (Nets / Lines, Non-Trawling)

NIGHT. A vessel at or near her masthead shows two all-round lights in a vertical line: RED OVER WHITE. She is making way, no trawl gear, working with set NET…

RULE 27(F)

Rule 27(f) — Mineclearance Vessel

NIGHT. A warship displays normal PDV lights (masthead + sidelights + sternlight) AND in addition THREE all-round GREEN lights one at the foremast head and on…

RULE 25(B)

Rule 25(b) - Sailing Tricolour < 20 m

NIGHT. A sailing vessel less than 20 m in length is approaching. She shows, at or near the top of the mast where it can best be seen, a SINGLE lantern combin…

RULE 25(E)

Rule 25(e) - Sailing AND Motoring

Daylight + NIGHT consideration. A vessel proceeds under SAIL and at the same time is being propelled by MACHINERY. What signal identifies this dual propulsio…

RULE 26(C)(II)

Rule 26(c)(ii) - Fishing with Outlying Gear > 150 m

NIGHT. A vessel engaged in fishing (not trawling) shows RED OVER WHITE all-round lights at or near the masthead AND, in addition, a WHITE all-round light off…

NARROW CHANNELS — RULE 9

RULE 9(A)

Narrow Channel — Keep Starboard (Rule 9(a))

You are transiting a narrow channel marked by the two dashed yellow lines on the PPI. Rule 9(a): keep as near to the outer limit of the channel on your STARB…

RULE 9(E)

Narrow Channel Overtaking (Rule 9(e))

You are in a narrow channel overtaking a slower vessel. Rule 9(e)(i): when you can overtake only if the vessel being overtaken acts to allow it, you signal y…

TRAFFIC SEPARATION SCHEMES — RULE 10

RULE 10(C)

TSS — Crossing at Right Angles (Rule 10(c))

You must cross a Traffic Separation Scheme whose lanes run NS (shown on the PPI). Rule 10(c): a vessel crossing traffic lanes shall do so on a heading as NEA…

RULE 10(B)(III)

TSS — Joining at a Shallow Angle (Rule 10(b)(iii))

You are joining the northbound TSS lane (right lane) from its east side. Rule 10(b)(iii): a vessel joining a lane from the side shall do so at as SMALL AN AN…

SAILING VESSELS — RULE 12

RULE 12(A)

Rule 12 — Sailing vs Sailing

Clear visibility. You are under SAIL with the wind on your PORT side (port tack). A SAILING vessel ahead has the wind on her STARBOARD side (starboard tack).…

VESSELS IN SIGHT — RULES 13–17

RULE 13

Overtaking (Rule 13)

Clear visibility. You are overtaking a slower vessel (you come from more than 22.5° abaft her beam). Rule 13: the overtaking vessel keeps out of the way — ei…

RULE 13

Being Overtaken (Rule 13 / 17)

A faster vessel is overtaking you from astern. The overtaking vessel must keep out of the way. Under Rule 17 you generally keep your course and speed unless …

RULE 14

Head-On Situation (Rule 14)

Clear visibility. A power-driven vessel approaches you on a reciprocal course, nearly right ahead. Rule 14(a): each shall alter course to STARBOARD so that e…

RULE 15

Crossing — You Are Give-Way (Rule 15 / 16)

Clear visibility. A power-driven vessel is on your STARBOARD side, crossing from right to left. Rule 15: you shall keep out of the way and, if circumstances …

RULE 17(A)(I)

Crossing — You Are Stand-On (Rule 17(a)(i))

Clear visibility. A power-driven vessel is on your PORT bow, crossing from left to right. You are the stand-on vessel. Rule 17(a)(i): keep your course and sp…

RULE 17(A)(II)

Stand-On — Last-Moment Action (Rule 17(b)(c))

Crossing situation target on your PORT bow is the give-way vessel but is NOT altering. Rule 17(a)(ii): as stand-on you may take action when it becomes appare…

RESPONSIBILITIES BETWEEN VESSELS — RULE 18

RULE 18(A)(IV)

Power-Driven Gives Way to Sailing Vessel (Rule 18(a)(iv))

AIS identifies the target as a sailing vessel (badge "S"). You are a power-driven vessel Rule 18(a)(iv): a power-driven vessel under way shall keep out of th…

RULE 18(A)(III)

Power-Driven Gives Way to Fishing Vessel (Rule 18(a)(iii))

Target is identified by AIS as a vessel ENGAGED IN FISHING (badge "F"). Rule 18(a)(iii): a power-driven vessel under way shall keep out of the way of a vesse…

RULE 18(A)(II)

Power-Driven Gives Way to Vessel RAM (Rule 18(a)(ii))

The AIS target reports "Restricted Ability to Manoeuvre" (RAM) e.g. a cable-layer or dredger (badge "R"). She is crossing from your PORT bow — between two po…

RULE 18(D)

Avoid Impeding Vessel Constrained by Draught (Rule 18(d))

The radar overlay shows a narrow DREDGED APPROACH CHANNEL (blue, ~0.8 NM wide, dredged to 16.5 m) with wider water around it (stippled, 57 m). Your draught i…

RESTRICTED VISIBILITY — RULE 19

RULE 19(D)

RV — Target Right Ahead (Rule 19(d))

Fog. Visibility under 0.5 NM. A target has been detected by radar right ahead, closing on reciprocal course. Take action in ample time. Rule 19(d)(i) prohibi…

RULE 19(D)(I)

RV — Target on Port Bow (Rule 19(d)(i))

Fog. A target is detected ~027° on the port bow (forward of the beam), closing with significant risk of collision. Rule 19(d)(i): avoid an alteration of cour…

RULE 19(D)(I)

RV — Target on Starboard Bow (Rule 19(d)(i))

Fog. Target detected on your starboard bow, forward of the beam. Rule 19(d)(i) forbids alteration to port. She is crossing ahead from starboard to port: a su…

RULE 7(B)

Radar — The True-Motion Trap (Rule 7(b))

Fog. Your radar is on TRUE MOTION with TRUE vectors. A ship on your starboard bow: her vector points away across your bow — she looks as if she will pass cle…

RULE 19(D)(II)

RV — Target Abeam Starboard (Rule 19(d)(ii))

Fog. A target is detected abeam on your starboard side (relative bearing ~090°), closing on a collision course. Rule 19(d)(ii): AVOID alteration of course TO…

RULE 19(D)(II)

RV — Target Abaft Port Beam (Rule 19(d)(ii))

Fog. Target detected abaft your port beam (relative bearing ~225°, 45° abaft the beam), closing. AIS identifies her as a SAILING vessel (badge "S"). Note: in…

RULE 19(E)

RV — Close Quarters Unavoidable (Rule 19(e))

You hear a fog signal forward of the beam. The target is detected close (about 2.5 NM) on a steady bearing. Keep at least 0.3 NM from her. Rule 19(e): when c…

RULE 19

RV — Multi-Target Encounter (Rule 19)

RESTRICTED VISIBILITY (fog, heavy rain, snow). You cannot see either vessel visually you only have radar/AIS. Rule 19 governs: there is NO stand-on/give-way,…

SOUND SIGNALS — RULES 34–35

RULE 34(A)

Rule 34(a) — Whistle Manoeuvring Signals

POWER-DRIVEN vessels in sight of one another use whistle signals to indicate helm actions (Rule 34(a)): (1 short, 1s) = "I am altering my course to STARBOARD…

RULE 34(D)

Rule 34(d) — Doubt / Disagreement Signal

POWER-DRIVEN vessels in sight of one another, when in DOUBT whether sufficient action is being taken by the other to avoid collision, shall indicate such dou…

RULE 35(A)

Rule 35(a) — PDV Underway in Fog

FOG. Visibility 0.3 NM. You are a power-driven vessel MAKING WAY through the water. Rule 35 requires you to sound specific signals at intervals of NOT MORE t…

RULE 35(C)

Rule 35(c) — NUC / RAM / Sailing / Fishing Fog Signal

FOG. You hear, at intervals of not more than 2 minutes, one prolonged blast followed by two short blasts: . Under Rule 35(c), which of the following vessels …

LIGHTS & SHAPES — RULES 23–31

RULE 30(A)

VHF SRC Radio Simulator 15 scenarios

Realistic Icom-style VHF radio panel. Practise voice Mayday, DSC distress alerts, Mayday Relay, Pan-Pan urgency, Sécurité safety and routine calls — exactly what your VHF SRC examiner will check.

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VHF SRC practice scenario.