Most cruisers who round western Finistere take the Chenal du Four and never give a thought to the Chenal de la Helle. That is a pity, because the Helle is a genuinely useful string to your bow. It runs parallel to the Four but further out toward the Molene archipelago, joining the main channel partway down, and on certain days and certain courses it is the tidier option. I keep it in my back pocket and have been glad of it more than once when the swell was running into the Four or when I wanted to cut a corner toward Molene.
It is not a beginner's first choice and it is not a soft option in bad weather. But understood properly, the Helle is exactly the kind of local knowledge that turns an anxious passage into a confident one.
What the Helle is and where it goes
The Chenal de la Helle is the channel that branches off toward the Molene archipelago, lying west of the inshore Chenal du Four and meeting it near the Les Plâtresses area. Where the Four hugs the mainland on the Saint-Mathieu and Kermorvan transit, the Helle takes a more westerly line before the two converge, which is why it can sit better with a westbound or Molene-bound course.
The whole western Finistere corner is a maze of rock, and both channels exist precisely because the clear water between the reefs is narrow. The Helle and the Four are reserved for fishing boats, pleasure craft and the French Navy, with Brittany Ferries permitted under certain conditions, so you share them with serious traffic and need to be where you are supposed to be.
The transit that defines it
The Four is built around the Kermorvan and Saint-Mathieu line on 158.5 degrees. The Helle has its own transit: the Kermorvan lighthouse paired with the Lochrist light marks the Helle route, distinct from the Saint-Mathieu pairing that holds you in the Four. Kermorvan, France's westernmost mainland lighthouse, is therefore a key mark for both channels, which is why getting the pairing right matters so much. Line Kermorvan with Lochrist and you are on the Helle. Line it with Saint-Mathieu and you are in the Four.
I keep the largest-scale SHOM chart open and confirm which transit I am actually on before I trust it, because mistaking one pairing for the other in the rock-strewn approaches is exactly the sort of error this coast punishes. The wider art of picking your way through this kind of ground is covered well in pilotage rock strewn brittany, which is worth reading before you attempt either channel for the first time.
Tidal timing, the same as the Four
The Helle joins the Four and shares the same tidal regime, so the timing logic is identical. The streams turn to the south at roughly HW Brest minus 0030, and the rates reach 4 to 5 knots and more in the narrows, so you plan to go with the stream and you reference the whole day to High Water Brest.
Everything in the chenal du four pilotage guide about slack windows and stream rates applies here, because once the Helle merges with the Four you are in the same body of water. And as with every gate on this coast, the coefficient sets the character of the day, so our explainer on reading a french tidal coefficient is as relevant to the Helle as to the Four itself. A high coefficient with wind against the tide makes either channel a place to avoid.
When I actually choose the Helle
I do not take the Helle as a default. I reach for it in specific circumstances.
The first is when I am bound for Molene or the Iroise islands rather than straight down to the Raz, because the Helle's more westerly line points me where I want to go without an awkward dogleg.
The second is when there is a westerly swell working into the inshore part of the Four and the more open Helle approach sits more comfortably on the day. This is a judgement call, not a rule, and it depends entirely on the sea state in front of me.
The third is simply traffic. If the Four is busy with ferries and fishing boats and I have a clean line on the Helle transit, taking the parallel channel can be the calmer choice.
When to leave it alone
The Helle is no place to be in poor visibility. It runs through worse rock than the inshore Four, and the transits that keep you safe need to be seen. In fog I take neither channel. It is also not a soft-weather refuge: a strong wind-against-tide day makes the whole western approach dangerous regardless of which channel you pick, and the answer then is to wait in L'Aberwrac'h or Camaret rather than to hunt for a cleverer route.
For a first passage through the corner, I would always learn the Four first. The Helle is the second tool you add once you know the area, not the one you start with. If you are still building toward this coast, the wider context in the north brittany cruising guide puts the western channels in their place within a season's cruising.
Working the transit in practice
The thing that makes the Helle worth learning, rather than just reading about, is how the two transits behave as you move through the approach. Coming from the north toward the convergence, you carry a westerly line down the Helle before the channel merges with the Four near Les Plâtresses. The Kermorvan and Lochrist pairing holds you until the merge, and then you pick up the main Four transit on Kermorvan and Saint-Mathieu for the run south to the Pointe Saint-Mathieu.
Going the other way, northbound, you have a genuine choice at the divergence: stay inshore on the Four's Saint-Mathieu line, or break out onto the Helle's Lochrist line for a more westerly exit toward Molene and the open Iroise. I make that decision early, with the chart on the table, rather than dithering in the rocks. Indecision is the enemy in this kind of pilotage, and committing to a transit and holding it is far safer than second-guessing halfway through.
One practical note: the leads here depend on being able to see the marks. The Lochrist light and Kermorvan need to line up visually, and in haze that can be harder than it sounds. I confirm the transit, note the back-bearing, and keep checking it against the chart as the marks open or close. If I lose the lead in poor visibility, the answer is not to improvise a course through the reefs, it is to abandon the Helle.
How it links into the corner
The Helle does not exist in isolation. It is one of three western tidal gates that a southbound cruiser threads in sequence: the Four or the Helle to clear Finistere, then the raz de sein timing to round the Pointe du Raz into South Brittany. Because they share the same HW Brest timing, a well-planned day can carry you through both on a fair stream, and the choice of Four or Helle is simply the first decision of that day rather than a separate exercise.
If your aim is Ushant rather than the run south, the Helle's westerly line also points you better toward the fromveur passage ushant and the islands of the Iroise, which is one of the most common reasons I take it. Either way, the Helle earns its place as the second route through a corner where having options is genuinely valuable.
The short version
The Chenal de la Helle is the inshore alternative to the Four for the cruiser who knows the corner.
- It runs west of the Four toward Molene and joins it near Les Plâtresses.
- Its transit is Kermorvan in line with Lochrist, not Saint-Mathieu.
- It shares the Four's tidal timing, turning south near HW Brest minus 0030.
- It suits Molene-bound courses and certain swell directions, not bad weather.
- It demands good visibility and a confirmed transit, every time.
Add it to your repertoire and you give yourself options where most visitors have only one. On this coast, options are worth a great deal.
