Temperatures on board are dropping and the pressure is rising with the fleet closing in on Boston. As the leaders leave the warm waters of the Gulf Stream behind, the sea temperature has plummeted.

But relief is in sight. In Boston, as the race village opens to the public today, the warm spring afternoon is forecast to approach the historical record high for the day.

Out on the race track, some 300 miles away, and as reported by Mark Chisnell in this morning's TEN ZULU, the leaders have been fighting through a ridge of high pressure for most of the day. Their progress has been slowed dramatically by the light conditions. The final miles to Boston will be hard-earned.

The battle to be first to finish has turned into a heavyweight tilt between the two Ericsson boats, with the Nordic crew landing a bruising blow early this afternoon, gaining some leverage to the north, and appearing on the 13:00 GMT position report at the top of the table. But now, just three hours later, Ericsson 4 have risen off the canvas and have managed to slide north to take up position six miles directly ahead of Ericsson 3.

"From sailing upwind in 20 knots of wind and bumping over the waves we have now almost stopped," reported Gustav Morin on Ericsson 3. "We have been going really well lately and the fight against the others is getting more and more exciting. Now even Ericsson 4 really have to watch out again."

The Ericsson twins aren't the only ones in this fight however. Telefonica Blue had crept back up to within 13 miles of the leader at one stage this afternoon, before sliding back on the latest poll. Skipper Bouwe Bekking has been making his best imitation of the ‘bobble-head' dolls that are popular handouts at the sporting events in this country, as he twists his head to look ahead at the Ericsson boats and then over his shoulder at PUMA, who went into StealthPlay this morning.

"The breeze has dropped rapidly, from one minute having 18 knots, to the next one having a mere 3-4 knots," the Telefonica Blue skipper reported. "So the big Code 0 is up again and we are rocking and rolling in the left over sea state. Where have seen that before in this leg? So another re-start is going to happen; both Ericsson Racing Team boats are roughly 20 miles ahead, and PUMA about 10 behind, but they are still sailing in the old breeze, and they might actually sail around us on the outside."

Could that be the reason for the StealthPlay aboard PUMA? These waters were the training ground for the PUMA team and they've spent many hours sailing here as media man Rick Deppe reported this afternoon.

"The approaches to Boston can be very tricky with numerous islands to navigate, we've sailed it a bunch of times during our training and Ken (Read) knows the area well," Deppe wrote. "I'm hoping that we'll get the chance to put this experience to some use... It sure would be nice to get on the podium in our home port."

Behind the leading quartet, there's a big difference of opinion between 'Wouter the weather router' on Delta Lloyd and his counterparts on Telefonica Black and Green Dragon.

The Delta Lloyd crew have bought themselves plenty of leverage to the north of the trailing pair, who are shadowing each other nearly 70 miles to the southwest.

For most of the day, all three were still moving well in comparison to the leaders, with speeds over 10 knots, compared to the leaders who had struggled all day to make even five. But this trailing trio aren't going to get off scot-free. The tables have turned on the 16:00 GMT poll, as they begin to negotiate the same ridge of high pressure. At the same time, the leaders appear to have escaped its grasp and are storming along - relatively speaking - at over 10 knots. The finish ETA for tomorrow is still projected to be late afternoon or early evening GMT.