In a flotilla the lead boat shows the way, but the collision rules bind every skipper. You need a handful of them: keep a lookout, know when there is risk, know who keeps clear, and make your move early.
How do I know if another boat is on a collision course with me?
Take her compass bearing, then take it again a few minutes later. A steady bearing while she gets closer means risk of collision; in doubt, assume it, and keep clear early with one large alteration.
Following the lead boat does not hand over your watch. Every vessel keeps her own lookout by sight and hearing, all the time, astern and under the genoa too.
To see whether a vessel will hit you, take her compass bearing, then take it again a few minutes later. A steady bearing while she gets closer is risk of collision. In doubt, assume it.
When you keep clear, do it early and boldly: one large change of course or speed that she sees at once and that leaves a safe distance. Small alterations tell her nothing.
Which yacht gives way when two boats under sail are converging?
The one on port tack keeps clear of the one on starboard tack; on the same tack the windward boat keeps clear. A boat overtaking from astern keeps clear of everyone, whatever the tacks.
Your tack is the side the wind comes over. When two boats under sail converge, the one on port tack keeps clear. On the same tack the windward boat keeps clear.
Overtaking comes first. If you catch another vessel up from astern, you keep clear until you are past, whatever the tacks and whether she is sail or power.
Port tack gives way to starboard tack, windward to leeward, and the overtaking boat to everyone.
Who gives way when two motor boats are crossing?
The vessel that has the other on her starboard side gives way: she turns to starboard to pass astern, or slows, and does not cross ahead. Meeting head-on, both turn to starboard and pass port to port.
Under engine you are a power-driven vessel. Meeting head-on, both turn to starboard and pass port to port. Crossing, the one that has the other on her starboard side gives way: she turns to starboard to pass astern, or slows, and does not cross ahead.
With the other vessel on your port side you are the stand-on vessel: hold your course and speed. If she does not act, sound five short blasts. If she still comes on, act yourself: slow down, stop or turn to starboard, never to port towards her.
Does a yacht motor-sailing have to give way to boats under sail?
Yes: with the engine in gear your yacht is a power-driven vessel, whatever sails are set, and keeps clear of boats under sail alone. By day she shows a black cone, point down, forward.
A power-driven vessel keeps clear of a vessel under sail, even one on her port side: the starboard-side rule is for two power vessels only. A sailing vessel in turn keeps clear of a vessel engaged in fishing with nets or a trawl.
The engine decides what you are. With it in gear your yacht is power-driven, whatever sails are set, and keeps clear of boats under sail alone. By day a motor-sailing yacht shows a black cone, point down, forward.
Do I have to keep clear of a ferry in a narrow channel when I'm sailing?
Yes: a sailing vessel, and any vessel under 20 m, must not impede a vessel that can navigate only inside a narrow channel (Rule 9). Keep near the starboard edge and move to the side early.
In a narrow channel, a canal or a strait, keep as near to its starboard edge as is safe.
A ferry or ship that can navigate only inside the channel has nowhere else to go. A sailing vessel, and any vessel under 20 m, must not impede her: "power gives way to sail" does not help you here. Move to the side early.
What do I do if I see a vessel's red light on my starboard bow at night?
Give way: that red is her port sidelight, so on a steady bearing she is crossing from your starboard side. Turn to starboard and pass astern of her.
A flotilla sails by day, but late arrivals happen. A boat under way shows a red sidelight to port, a green one to starboard and a white sternlight. A power-driven vessel adds a white masthead light, the steaming light, above them.
Red is her port side. On your starboard bow, on a steady bearing, she is crossing from your starboard: turn to starboard and pass astern of her.
Under sail a yacht under 20 m may show the three colours in one tricolour at the masthead. Under engine switch on the steaming light, sidelights and sternlight, and the tricolour off.
What do three short blasts from a ship or ferry mean?
My engines are going astern: a ferry at the quay sounding three short blasts is backing out, so keep away from her stern. One short blast means altering course to starboard, two short to port.
A short blast lasts about one second, a prolonged blast four to six. Power-driven vessels in sight of one another signal their manoeuvres; in fog a vessel under way sounds her signal at least every two minutes.
| Signal | Meaning |
|---|---|
| 1 short | I am altering course to starboard |
| 2 short | I am altering course to port |
| 3 short | My engines are going astern |
| 5 short or more | I doubt you are doing enough to keep clear |
| Fog: 1 prolonged | Power-driven vessel making way |
| Fog: 1 prolonged, 2 short | Sailing, fishing or towing; not under command, restricted in her ability to manoeuvre or constrained by her draught |
Three short blasts from a ferry at the quay: she is backing out, so keep away from her stern. A prolonged blast coming closer in fog is a vessel under power: slow down and listen.
Questions from this topic, as the app asks them. Open one to see the answer.
You are following the flotilla lead boat across to Kalamos. Your crew say, "Just follow them — they keep watch." What does Rule 5 require?
A. You keep your own lookout at all times
Rule 5: every vessel keeps a proper lookout by sight and hearing at all times.
Both yachts are under sail and converging. Who keeps clear?
B. You — you are on port tack
Rule 12(a)(i): on different tacks, the port-tack boat keeps clear.
You are motoring. What do you do?
A. Hold your course and speed
Rule 15: she has you on her starboard side, so she gives way; you stand on (Rule 17).
Sailing off Preveza, you are converging with a boat showing this shape. Who keeps clear?
C. You — she is engaged in fishing
Rule 18: a sailing vessel keeps clear of a vessel engaged in fishing.
Sailing through the narrow strait at Poros, you meet this ferry. Who keeps clear?
A. You — do not impede her in the channel
Rule 9(b): a sailing vessel must not impede a vessel that can only navigate in the channel.
You are motoring at night and see these lights. What do you do?
D. Alter to starboard — she is head-on
Rule 14: a masthead light and both sidelights dead ahead mean head-on; both turn to starboard.
All 20 questions of this topic are in the app: practice by topic with the reason after every answer, your mistakes brought back, and a timed mock exam. Free, no sign-up, in the browser or in Telegram.