Enveloped in an atmospheric pea-souper fog, with less than 300 metres of visibility and very low cloud, the 11 Imoca monohulls set off from Calais at 1430 hours (local time) on a clockwise rotation of the British Isles.

With 10 knots of northerly breeze, the fleet split into two sail configurations, half under full main, gennaker the others under asymmetric spinnaker. Jean Le Cam (VM Matériaux) was first to steal across the start line under gennaker, closely followed by Vincent Riou (PRB) under spinnaker.

The outlook for this third edition of the Calais Round Britain Race is set to be very tricky for the navigators in particular, the latter needing to spend a considerable time at their chart table pouring over the numerous transition phases. Initially obliged to hug the northern coast of France, the fleet rounded the Boulogne mark at around 1730 hours. PRB was setting the pace, closely followed by Temenos and Delta Dore.

A difficult night lies ahead of the fleet as they tackle a zone of high pressure without much wind to the south-east of the Isle of Wight at around midnight. Crews will then have to choose whether to take a central and more direct route, or try to slide downwind in an easterly air stream. A third option will be to dive under the direct route to round the zone of light wind, thus extending the trajectory but benefiting from some headwinds.

By morning the fleet is likely to be fairly dispersed and not very well rested, particularly after the stress of such close contact sailing at the start in the fog… Last seen breaking away from the Boulogne mark on route for the Scillies, the fleet were blistering along at 16/17 knots as we go to press tonight.

At the head of this colourful fleet tonight, the new PRB is surely one of the most honed and well-trained teams on the Imoca circuit, as their double win in the two prologues bears witness. Multi-talented sailor and crew Sébastien Josse explains the secrets of their success. “Since the boat’s launch two months ago, all five of us have sailed aboard a lot. We’ll see if this extra training bears fruit. We have also carried out a fair amount of development on the sails so we’ll see if all that work has been in the right direction or if we need to make further modifications. Over 2,000 miles, there are periods where you will really be able to compare the potential of the boats. We’ll be able to study speeds and wind angles and see if we’re on the right track or not. It’s going to be intriguing.”

Currently in second position, the Swiss skipper of Temenos, Dominique Wavre, last night admitted: “I’m a competitive regatta sailor through and through and I really want to do the boat (an Owen Clarke Design) justice.” Leading PRB, Delta Dore, and Generali five miles from the start this fighting spirit is very much in evidence.

Dropping from fifth to eighth position on the approach to Boulogne, the forecast according to Australian Paul Larsen on the five-year-old Artemis (formerly Pindar), suggests that: “the exit from the Channel won’t be a powered up drag race. It’s going to be a parking lot with all the tidal gates.”

Clearly the current 16/17 knots boat speed of the leaders is unlikely to last tonight and Dee Caffari on Aviva alluded to a possible need for kedging over the course of the night.

Sixth at the mark the all-girl crew on Roxy were realistic about the capacities of the souped-up seven year old Finot Conq design prior to the start. “It’s clear from the routing software that we mustn’t despair when we see the other boats take off, because there are likely to be a number of restarts. Our aim will be to stay in touch and then stay smart and pounce when we can. Some boats are definitely faster but what has been interesting over the two prologue races over the last couple of days is that we’re not that much slower, which is awesome. There are some big currents around here so it’s going to be technical and we won’t be able to follow the normal laylines for sure. I have this feeling that we’ll come good?but it won’t be until further down the racetrack?!”

Further down that racetrack the big question is air or no air. Once past the front, which is gradually dispersing as it moves eastwards, the sailors will benefit from a northerly air flow to the south of the Isle of Wight after sunrise on Monday. These winds should hold for part of the day, the pace of the fleet accelerating to Bishop Rock lighthouse, off the Scilly Isles. The northerly wind is then forecast to build to 15 knots? The crossing of the Irish Sea will be quicker since the breeze will climb to 20 knots as it clocks round to the north or north-east. On reaching Ireland, the fleet will hit a very light patch, possibly enabling the back-runners to make big gains on the leaders.

The routing software simulating the progress of the 11 monohulls show the leaders reaching the south-west of Ireland on Tuesday 5 June at around 2000 hours (French time), the Shetland Islands between sunrise on Saturday 9 June and Sunday 10 June at noon? As for the finish in Calais, predictions favour midday on Monday 11 June to Tuesday evening.