| NEW !! The same routing program used in our "Force 4" tactical program is now available in our "Offchart Racer" program for just $695, AND Offchart Racer is now available for FREE evaluation. Download Offchart Racer |
| RECAP OF LEG ONE OF VOLVO OCEAN RACE. After more than 7000 nm, Illbruck and Amer Sports One ended up in almost a photofinish, with Illbruck passing a day out and finishing some two hours ahead. |
| Comparison of Illbruck's
route and the "Force 4" Routing Solution. The red line shows the Force 4
solution, beginning from the position "1" of Illbruck at 0400 on 9/25. The green
boxes show reported Illbruck positions to point "8" at 1000 on 10/1. Yellow box
"6" shows the predicted position for the F4 solution at 1000 on 9/29, slightly
to the west of Illbruck's "6." Actual and predicted positions at
"8" coincide. To this point Illbruck has closely followed Force 4's optimal
route. After 1000 on 10/1 Illbruck's actual route deviated sharply to the southwest, arriving at "12" at 1000 on 10/5. Predicted locations on the optimal route at comparable times are shown by the series of points "9" to "12" on the red line. By 1000 on 10/5 Illbruck was more than 400 miles to the north of her potential location, held up in light air but covering the bulk of the fleet behind her to the north and west. Only SEB, who had to divert and anchor briefly for repairs at Porto Santo (to the southeast of point "7"), was in a position to take advantage of the much stronger winds off the coast of Mauritania reflected in the Force 4 routing. SEB made large gains from well behind to take over the lead on 10/6 (see detail below). Fortunately for Illbruck, SEB was not able to get past another region of light air in the days ahead, and Illbruck retook the lead and held it past Ilha Trindade. |
 |
| Routing from Fernando I to
Ilha Trindade was an easy call, a sprint along the rhumbline. From there to Cape Town, the
major decision was to go above (north) of a high lying along the direct route, or to go
below (south) of it. The Force 4 solution strongly favored the southern route, and all
boats chose this except Assa Abloy. Below we compare the Force 4 routing solution from Ilha Trindade to Cape Town, beginning at 0800 on 10/15, and compare it to the actual track of Illbruck (series of points from "1" to "11"). There is little predicted time difference for a narrow band of routes (red, magenta and yellow) bending south of the rhumbline, but a large difference for more northerly routes. Illbruck closely followed the predicted optimal route, as did Amer Sports One, who held onto a slim lead until Illbruck was able to overtake her in the final hours. |
 |
| Detail of 10/15 routing solution compared to tracks of Illbruck (lower numbered points) and Assa Abloy, who originally headed east along the much slower "green" route (upper numbered points at corresponding times). Wind vectors are shown as predicted at 1000 on 10/18, at which time the boats reached their respective point "4." Assa changed course to the southeast on the third day, but too late. Illbruck's route had brought her into strong winds on the port beam, ranging to 20 knots (magenta arrows SW of "5"), whereas Assa Abloy faced days of winds in the 10 knot range. At this point there still was a glimmer of hope, as some forecasts briefly predicted a high drifting to the southwest of Cape Town which would have parked the leaders on their approach and given Assa a chance to catch up. However, this possibility evaporated the next day and actual conditions for Assa became even worse as she dropped hundreds of miles behind. |
 |
| A CRITICAL MOMENT, where Illbruck took the lead early on. Routing solution from position of Tyco at 1000 on 10/1 (yellow box underlying green box "1"). Set of points to left is Tyco, to its position "10" at 1600 on 10/4. Set of points to near right is Illbruck, and far right is SEB, all at corresponding times. Illbruck separated some 17 nm to the east in the early evening of 10/1, enough to pick up a bit more wind and take the lead from Tyco the next day. This gain was modest compared to that of SEB, which started further east and sailed into the much stronger winds along the optimal "red" route. Illbruck had position a bit to the south and east of the fleet behind her, and played it safe. The interesting question is why none of the boats behind her headed east to the passing lane, which persisted for day after day of forecasts. |
 |
| A MISSED OPPORTUNITY? After rounding Ilha Trindade on 10/15, Illbruck had fallen a mile behind Amer Sports One by 0400 on 10/16 (point "1" below). From there the boats followed very similar tracks, with AS1 ahead by 29 nm at 0400 on 10/18 (point "5" below). At each timepoint, AS1's position is slightly below (south of) Illbruck. The routing solution, however, finds much better gains to the east. The black dots on each colored route show predicted "boat" position at 0400 on 10/18 (wind vectors are also shown at that time). Compared to the actual position of AS1 (yellow box "5"), the black dot on the optimal red route is 125 nm closer to Cape Town, reflecting the stronger winds to the east. If AS1 had tried a more eastward track, it might have picked up the extra miles needed to hold off Illbruck and get the win. |
 |
| SEE NEXT LEG DAILY ANALYSIS BEGINNING Nov 11: DAILY PAGE |