PASSAGE PLANNER

Chenal du Four and the Raz de Sein

The most exposed part of this passage is between L’aber Wrac’h and Le Four. The whole area is prone to fog. Tides are key to timings:

CHENAL DU FOUR

The tide turns at St-mathieu earlier than it does in the north of Le Four. Southbound this is a nuisance because the early part of the south stream runs to waste. Northbound the tidal lag is a benefit and extends the fair tide by a couple of hours. Plan for a favourable tide for as much of the Four as timings allow, but if winds are on the nose aim to go through the narrow part between Le Conquet and St-mathieu at slack because wind over tide here can create very steep seas, particularly at Springs when the stream can run at up to 5 knots. If you need to sit out the tide there are anchorages in Anse de Porsmoguer, Portz-illien or Anse des Blancs Sablons. On a first passage, in bad conditions or in poor visibility it is better to stick to the channel markers and leading lines, but be aware that in poor visibility the marks themselves become a hazard.

RAZ DE SEIN

Tidal streams across the Iroise are generally weaker than in the Four or through the Raz. Aim to be at the Raz at slack water with the turn to your favour. If you arrive at the end of the tide you risk the gate closing against you. If this happens the safe options are Morgat or Douarnenez. In settled weather anchorages on Île de Sein or in Baie des Trépassés are also a possibility. The Raz can be rough even in moderate conditions, and in strong wind against tide the overfalls become dangerous. At neaps, with calms or light winds and with no swell it is less turbulent, but you would want to feel confident in your engine should it be needed.

CHARTS AND TIDAL STREAMS

Imray C18, C35, C36, C37 Chart Pack 2510

SHOM tidal stream atlas 560-UJA Imray Tides planner app

PILOT BOOKS

Atlantic France, Nick Chavasse/ RCCPF, (Imray, £42.50) Secret Anchorages of Brittany, Peter Cumberlidge, (Imray, £29.50).