The first time I crossed the Ushant rail I had read all the books and still got it wrong in the head. I expected a wall of ships. What you actually get is more unsettling: long gaps, then a 300-metre container ship coming out of the murk at 20 knots, and you with maybe twelve minutes to decide whether your closing geometry is a problem. The two great traffic separation schemes that bracket the western and central Channel, off Ushant in the west and the Casquets in the middle, are not difficult to cross. They are difficult to cross casually, and casual is exactly what a tired delivery crew tends to be.
What the Ushant scheme actually is
The Ouessant (Ushant) TSS sits off the most westerly point of France, where everything bound up-Channel or down toward Biscay and the Atlantic funnels through. On a normal day around 120 cargo ships of nearly 90 different flags pass through it. The scheme is built from two one-way lanes, each five nautical miles wide, separated by a buffer zone of about the same width. The lane nearest the island carries traffic heading into the Channel; the outer lane carries the outbound stream. There is also an inshore traffic zone between the lane and the coast, which is where smaller vessels and local traffic are meant to keep.
It exists because of a disaster. The Amoco Cadiz broke up off Portsall in 1978 and dumped its cargo along the Breton coast, and the rail you cross today is the regulatory child of that wreck. Treat the lanes with the seriousness that history earned.
The whole area is watched from ashore. CROSS Corsen runs the Ouessant VTS, a mandatory reporting system covering a 35-mile radius centred on the island. Corsen broadcasts traffic information in French and English on VHF channel 79, with an announcement first on channel 16 telling you when and where the next bulletin will come. Before you ever enter the lanes, you should have that channel up on a second set and a rough picture of what is moving.
Halfway across, the Casquets
Roughly halfway along, off Alderney and the Casquets rocks, sits the second scheme you are likely to meet on a Channel passage. This one is watched by CROSS Jobourg from the tip of the Cotentin peninsula, which surveys the Casquets TSS, coordinates rescue, and acts as the reference centre for marine pollution. Jobourg broadcasts its traffic bulletins at 20 and 50 minutes past each hour. I have sat hove-to off the Casquets and counted close to 40 ships visible at once on a clear morning, which puts the density into perspective: this is not a place to be working out your strategy on the hoof.
The Casquets lanes feed the same up-Channel and down-Channel streams that you will meet again, much tighter and faster, in the Dover Strait traffic separation scheme for small craft two hundred miles to the northeast. If you are doing a full passage, you may cross all three. The rules are identical; only the spacing and the speed of the ships change.
The rule that matters: cross at right angles
Rule 10 of the collision regulations is short and unforgiving. A vessel crossing a traffic lane shall do so as nearly as practicable at right angles to the general direction of traffic flow. Not at right angles to your course made good, not at a comfortable diagonal, but a heading that puts your bow square across the lane.
This trips people up because tide sets you sideways. If you steer to counter the tide and follow a tidy track across, your heading ends up skewed and you spend far longer in the lane than you need to. The point of the right-angle rule is the opposite: you let the tide carry you, you keep your heading square, and you accept that your ground track will be a slanted line. A watching ship sees your aspect change quickly and reads your intention. That is the whole purpose.
Practical numbers. At five knots through the water, a single five-mile lane takes you an hour to clear. Both lanes plus the separation zone is the thick end of three hours of exposure. Plan the crossing for a stretch of fair tide and daylight if you possibly can, and pick a heading before you commit, not while a bulk carrier is filling your view.
Reading the traffic before you commit
- Get AIS up and running and actually look at the CPA and TCPA figures, not just the pretty triangles. A ship at 20 knots covers a mile in three minutes.
- Make your VHF bulletins part of the routine. Corsen on 79 in the west, Jobourg at 20 and 50 past in the middle.
- Cross the near lane, then reassess in the separation zone. You are allowed to pause your mental clock there. Sort out the far lane as a fresh problem.
- Never assume a ship has seen you. Many will, some will not, and a yacht is a small radar target in any sea.
If you are crossing as part of a longer hop, the same discipline applies to the whole passage. My notes on crossing the English Channel by boat go into the weather-window and tidal-gate side of it, and what I learned about timing the western approaches feeds straight into how you plan the Ushant rail.
Night, fog and the things that go wrong
Fog is the real hazard out here, not the ships themselves. A clear day off Ushant is manageable with a working brain and a working AIS. Fog removes your eyes and leaves you trusting electronics and a radar reflector. If the visibility closes in, the watching centres step up their broadcasts, and you should slow down, sound your signals, and consider whether crossing at all is sensible right now. There is no medal for pressing on. If thick weather catches you between the lanes, my account of what to do if fog catches you mid-Channel covers the tactics I fall back on.
The other failure mode is fatigue. Two-handed crews on a long passage hit the Casquets scheme tired, often at night, and that is precisely when the right-angle discipline slips. Brief it before you are inside the lanes. Agree who is watching AIS, who is steering the heading, and what the bail-out is.
Inshore traffic zones and the temptation to dodge
There is a tempting shortcut here: rather than cross the lanes at all, keep inshore of them in the inshore traffic zone and follow the coast. Sometimes that is exactly the right call, particularly off Ushant if you are coasting rather than crossing. But the inshore route past Ushant runs you into the Fromveur and the Chenal du Four, tidal passages with fierce streams and a rock-strewn margin that demand their own timing and pilotage. You trade the open-water problem of big ships for the close-water problem of tide and rock. Neither is harder than the other; they are simply different, and you should choose deliberately rather than drifting inshore to avoid a decision. If the inshore option appeals, plan the tidal gates with the same care you would give the lanes.
The other thing the inshore zone is not is a refuge for crossing traffic. If your passage genuinely takes you across the streams, cross them properly at right angles and do not hug the boundary of a lane hoping to sneak along the edge. That is exactly the behaviour that confuses a watching ship and the watching shore station alike.
A short checklist before you enter
- Tide computed, fair stream if possible, heading chosen for a square crossing.
- VHF on the right channel, traffic picture heard, not guessed.
- AIS confirmed transmitting and receiving, CPA alarms set sensibly.
- Radar reflector up, navigation lights checked if there is any chance of being there after dark.
- Crew briefed: this is an hour or more of full attention per lane, not a moment to make tea below.
The Ushant and Casquets schemes have a fearsome reputation among first-time Channel crossers, and most of it is misplaced. The ships are predictable. The lanes are charted. The rule is one sentence. What kills the reputation stone dead is doing the homework, holding your heading, and respecting the fact that 120 ships a day will not be slowing down for you. Get those right and the crossing becomes the dull, satisfying hour it ought to be.
