How did a 1968 boat with a handful of GRIBs lead the fleet for a week?

For the first week of the 2022 Round Britain and Ireland Race, my 1968 S&S 34 Morning After led the entire IRC fleet on corrected time. She was the oldest boat in the race, a sister ship to Ted Heath’s famous Morning Cloud , and averaging around five knots. Our communications were basic (and expensive) that we downloaded only a handful of GRIBs throughout the race.

Morning After: five knots, a handful of GRIBs and the front of the fleet.

For readers outside the UK, the Round Britain and Ireland Race is a 1,805 nautical mile, non-stop circumnavigation of Britain and Ireland. First run in 1976 and now held every four years by the Royal Ocean Racing Club, it is roughly three times the length of the Fastnet or the Sydney to Hobart and reaches as far north as the Shetland Islands. The yachts race under IRC handicap, allowing a 34-foot boat from 1968 and a modern 60-footer to compete on corrected time. The 2026 edition starts from Cowes on Sunday 9 August. Our week at the front, in 2022, does not prove that less weather data makes a boat faster. I cannot show that we led because we had fewer downloads, and I cannot establish what every other boat received. What I can describe is the discipline that our limited communications imposed on us. We could not respond to every new model run because we did not have one. We had to decide which information could alter the race we were actually sailing and which described a future our boat could not yet reach. We listened to the radio weather reports and had a digital version of the old fax weather reports and looked at the barometer to judge the changes in pressure, much like navigators have always done. That discipline, rather than the shortage of data itself, may have helped to keep us at the front, it was also upwind and light and we were able to maximise on the beautiful design by Olin Stephens that have always made his designs fly upwind. We finished by winning our class but not the race. We did not hold the overall lead to the finish, which tells you something too. Modern designs such as the Sunfast range of boats are the exact opposite to and an S&S design they are excellent downwind. But let’s get back to the point of this article which is about using tech correctly I wrote recently about what a GRIB actually is, a simplified mathematical opinion of the future atmosphere, not a promise. That article was about the forecast itself. This one is about what a navigator does with it, and how far ahead anyone should commit when the boat is the limit on what can be acted upon. Our challenge was not what we could forecast. It was what the boat and I could actual do with the data. Most IRC yachts on that course will average somewhere between five and ten knots. At six knots, a yacht covers about 140 nautical miles in 24 hours. An Atlantic depression may travel 300 to 400 nautical miles in the same period. No volume of satellite bandwidth changes that arithmetic.

The forecast horizon and the boat’s decision horizon are not the same thing.

OK, this is a simplification to demonstrate the point: That does not make the longer-range forecast irrelevant. A moving weather system may create an opportunity precisely because it is moving faster than the boat. The navigator may need to position for it days before it arrives. But a forecast horizon and a decision horizon are different things. The forecast horizon is everything the models can show. The decision horizon is the part of that forecast the boat can act upon with enough confidence to justify a commitment. Beyond that point, the navigator is working with scenarios. Those scenarios still matter, but they should not be mistaken for instructions. Long-range information shapes the strategy. Nearer-term information determines the commitment. There were points during the 2022 race when we could see that the breeze ahead was likely to collapse. Knowing that did not automatically give us a course capable of changing the result. We were not going to outrun a moving weather system at five knots, and we could not sail another hundred miles into better pressure before that pressure moved somewhere else. We stopped spending energy on the part we could not influence and concentrated on the part we could. We sailed the weather in front of us as well as possible. We kept the crew fed and rested. We found half a knot through better trim and cleaner manoeuvres. None of that appeared on a routing screen. All of it kept us at the front and decided our class result and we didn’t fret over what we could not control

Morning After. The decisions that moved Morning After through the fleet rarely began with a new line on a screen.

Modern routing software is extraordinary, and I use it. But mathematical precision is not the same thing as forecasting certainty. ECMWF explains that forecast skill decreases with lead time for two reasons: uncertainty in the initial conditions and unavoidable approximations in the model. Both sources of error amplify with time. How quickly usefulness fades depends on the weather pattern, the variable being forecast, the location and the decision being considered. There is no universal cliff at 24 hours, 48 hours or five days. Predictability is different for every situation. Ensemble forecasting helps by exposing that uncertainty. It does not remove it. A single route drawn across a screen can conceal a wide range of possible outcomes behind one apparently precise line. Every routing result is therefore an answer to a conditional question. If the forecast, the boat polars and the assumptions are correct, what is the quickest route? Change any of those assumptions and the answer changes.

Morning After in 2022. Taking a more western route

Aboard Morning After , detailed planning beyond 24 to 48 hours rarely earned its keep. We still monitored the developing pattern and considered the routes it might create. What we avoided was repeatedly committing to detailed changes based on weather that would probably evolve before we could reach it. A low forecast to pass north of Scotland in six days may arrive earlier, later, deeper or on a different track. The routing may have been correct for the forecast it was given. That did not make the forecast certain. Richard Palmer understands this from the sharp end of the same race. He and Rupert Holmes won the 2022 Round Britain and Ireland Race overall aboard the JPK 1010 Jangada . After almost fifteen days at sea, they beat the second-placed boat by seven minutes and nine seconds on corrected time. Their margin came down to the final hours. Once their closest rival, Bellino , had finished, Palmer and Holmes had a fixed corrected-time target. Palmer later told Yachting World that the routing predicted they could reach it with two minutes to spare. He woke Holmes and they went for it. That is routing used exactly as it should be: over a matter of hours, against a fixed target, with current information. It was helping two sailors execute a decision, not replacing their judgement with the apparent precision of a five-day route.

Jangada crossing the line in Cowes. The winning margin was seven minutes and nine seconds after almost fifteen days at sea.

None of this means ignoring the longer-range picture. Before the start, I want the whole strategic map. I want the synoptic pattern, the likely transitions, the major tidal gates and the areas where opportunities may develop. I want to understand the alternative scenarios and what would cause us to move from one to another. Once the gun goes, I keep monitoring that developing picture. My detailed commitments narrow hard. Can we carry this sail for another hour? Should we reef now rather than wait? Is the crew eating and sleeping properly? Can we find half a knot through better trim? Has the new forecast changed the decision, or merely moved the line on the screen? Those are questions that can be answered with useful confidence. Five days out, a route is a scenario, not a set of instructions. Technology encourages action. Every fresh GRIB seems to demand another routing run. The software produces a different line, so the navigator feels obliged to do something different. Sometimes the new run changes the decision. Sometimes it changes only the drawing. The important question is not whether the route has moved. It is whether the evidence has crossed the threshold required to change what the boat should do. That is why doing nothing can be one of the hardest decisions a navigator makes. Not because the information has been ignored, but because it has been examined and found not to change anything that matters. Offshore races are rarely won by one brilliant routing call. They are won the way Jangada won in 2022 and the way Morning After remained at the front for the first week: through a long accumulation of slightly better decisions, made close enough to the moment that they could still be executed. The people making them trusted their judgement more than the screen’s apparent precision.

Navigator’s Rules • Understand the whole race before the start. • Monitor the whole developing picture. Plan the next 24 hours in detail. • Treat routes beyond the decision horizon as scenarios, not instructions. • Know what every extra mile is buying. • Question every routing change. Ask what has actually changed. • Concentrate on boat speed, crew condition and decisions that can still be executed. • Hundreds of slightly better decisions beat one brilliant idea.

The 2022 race - the biggest divergence of routing was in the North Sea once the wind had freed and spinnaker were hoisted as class 1 and 2 rounded Muckle Flugga

For those starting on Sunday If I were navigating this year’s race, I would study the whole course before the start, keep watching the pattern develop, and commit in detail only to the next 24 hours. But since most of you reading this will be on the water rather than watching, three specifics from 2022 that I would want in my back pocket. Sail the shortest route between waypoints, and know when you are choosing not to. Extra miles are never free; they are a purchase, and the navigator should be able to say at any point what the purchase is buying. Plan every tack. On a 1,805-mile course the habit of asking “what is the direct line, and why exactly are we off it?” is worth more than any single routing run. Most of the fleet will be flying asymmetrics, and that sharpens the arithmetic. An asymmetric boat sails hotter angles downwind, which means more distance through the water for the same distance made good, so your polar discipline and your extra-miles discipline are the same discipline. In light conditions that margin tightens further, and in the North Sea it meets the tide. A few per cent of unnecessary distance arriving at a tidal gate on the wrong state of stream does not cost you a few per cent; it can cost you six hours, and six hours in this fleet is the race.

The Thames Estuary and the run into Dover and then home! It’s a major part of the navigators job, after many days at sea, to make this work well… plan ahead and know at least three different routes depending on arrival times at the Sunk and Goodwin

And do not mentally finish the race at the Thames Estuary. The temptation after nearly two weeks at sea is to treat the run home as a procession, but the route through the Sunk, south past the Goodwin Sands and on past Dover is never straightforward: sandbanks, shipping, strong streams, and a tired crew making decisions they would not have made in the first week. Remember what decided the 2022 race overall: seven minutes and nine seconds, settled in the final hours. The race is not over at the Estuary. It is often just lost there.