Teams are re-emerging from a quiet but productive winter and beginning to make some noise around Valencia again. To date, nine yachts have been or are in the process of being constructed to the new Version 5 rules. Luna Rossa launched their new hull recently, and ITA-86 has been seen exiting the America's Cup Basin wearing a full-length skirt around her nether regions. As of 1 January 2006, the teams are allowed to disguise their hulls with skirts until the beginning of the Louis Vuitton Cup Challengers Series in April 2007.

After the mini-skirt sported by Australia II in 1983 to keep the famous winged keel from prying eyes, Team New Zealand took the practice to a new level in Auckland 2003 when they used a full-length skirt to hide the ‘hula', a design breakthrough that ultimately proved irrelevant. Whether or not Luna Rossa and others feel they are going to be disguising crucial elements of their new boats from other syndicates, or whether they are simply playing mind games is never really clear. Some sailors like the air of mystery and intrigue that ‘skirting' brings to the America's Cup, but getting the boat dressed and undressed each day is nothing but a pain for shore crews and sailing teams.

Another rule came into effect on 1 January, which prevents anyone working for more than one team between that date and the end of the America's Cup in July 2007. For some of the smaller teams in particular, whose financial futures remain far from clear, this means a number of sailors have not been working there since the beginning of the year. Sailors don't want to preclude themselves from other offers if the future of their existing contract is looking shaky.

Victory Challenge was reputed to be very close to packing up shop and going home to Sweden, but there appears to be a new, albeit limited, drive to keep the show on the road. Killian Bushe, the Irish boatbuilder who has done such a good job with the ABN AMRO boats currently dominating the Volvo Ocean Race, has been tasked with making extensive modifications to Victory's existing hulls from the 2002/03 Cup, SWE-63 and SWE-73. The Mani Frers designs have shown good potential in their original form, and since Version 5 is not a massive step on from Version 4, this seems a good halfway house solution for a team struggling to stay in the Cup.

The team that most appears to be dying a slow death is the Italian Challenge +39, with British skipper Iain Percy and his sailing team having worked without pay for many months, and all boatbuilding projects on hold. With the strong British contingent within the sailing squad, there has been talk of whether a white knight might sweep in from London and save the campaign, but things are certainly looking bleak for the team right now.

There is little getting away from the mind-boggling expense of mounting even the humblest of America's Cup campaigns, let alone one that stands a chance of winning it. But America's Cup Management (ACM) have done well to reduce costs in a few areas, notably in establishing a centralised weather data gathering unit.

Whereas in previous Cups, each team has been responsible for running its own weather-gathering programme at great expense, the aim of ACM's Meteorological Data Service (MDS) is to avoid that needless doubling up of resources. MDS manager Glyn Davies has worked on many weather programmes in past Cups, including Alinghi's last time round.

Davies explains the rationale of the new centralised approach to collecting weather information: "In the last Cup you'd be out there on your weather boat gathering data, and you'd be surrounded by weather boats from all the other teams, all within 100 metres of each other. We'd all be out there, gathering exactly the same information."

There were also a number of battles over weather buoys sitting out on the Hauraki Gulf, as to who had access to the data from those buoys. Teams were spending a small fortune trying to put one over each other in gathering the most reliable information. Davies estimates that a weather programme in Auckland, with typically a fleet of seven weather boats plus associated staff, would have cost at least a million New Zealand dollars - or in excess of half a million Euros. "This time we calculated that a similar weather programme for Valencia would have cost in the region of 1.3 million Euros," he says.

Alinghi and BMW Oracle, as the Challenger of Record, both agreed very early on that a centralised weather programme was the way to go. But the actual format of the programme, and particularly the distribution of the buoys in and around the race course, was still a cause for heated debate between the Swiss and Americans. In the end a compromise was reached, and MDS was born.

Rather than using a flotilla of weather boats and all the associated costs, Davies and his MDS colleagues have developed 21 purpose-built weather data buoys which will be permanently located in and around the North and South race courses. The North course has had eight buoys operational for almost a year now, and were used during the Acts in Valencia last summer. By the beginning of this year's Acts in May, Davies plans to have the whole network of 21 buoys fully up and running. The past two years getting to this point have been gruelling, with Davies and his five colleagues sometimes working 100-hour weeks to have the system ready in time. "I can't tell you how much I'm looking forward to the racing starting this year," he says.

But so far so good for the technology. Davies says that after some initial objections, the MDS system has gone down very well with the teams. There was a fear among some of the challengers that a centralised system controlled by ACM - and therefore by association Alinghi - might play into the hands of the Defender. On winning the Cup, Ernesto Bertarelli divided the management of the Cup from the defence of the Cup, and so a separate entity was born in the form of ACM. But can they really be trusted, particularly in such a sensitive area as weather data?

"There's no question of that," Davies argues. "You should hear some of the arguments we have with Alinghi!" He says there have been a couple of times when he's discovered challengers trying to catch MDS out, in a bid to test the trustworthiness of the data. "They haven't caught us out because there's nothing for them to catch us out on," he asserts.

As teams have come to grow trust in the system, so too have they been impressed by the accuracy of the data. Contractually, MDS was expected to achieve an accuracy of wind direction readings of +/- 5 degrees, which Davies says was about par for the course in Auckland last time. The MDS buoys are achieving an accuracy of +/- 3 degrees. In terms of measuring true wind speed, contractually the requirement is +/- 5%, but by using hi-tech sonic anemometers the buoys are sending back data that is accurate to within 2%. The buoys do a solid working day from 9am to 5pm, between which times they send back new data every 15 seconds, and then for the overnight period from 5pm to 9am they continue to update every 5 minutes.

This sort of accurate, round-the-clock data is gold dust for yacht and sail designers. It allows them to analyse the predicted windspeed for the America's Cup and design their boats accordingly. But as Davies points out, MDS is only a real-time weather gathering service, it doesn't forecast the wind. And as Team New Zealand learned to their cost last time in March 2003, the predicted light airs for the America's Cup finals didn't materialise. When the wind and waves kicked up, neither hull nor mast proved man enough for the job. While carbon creaked and crashed around their ears, Alinghi stormed off to that famous 5-0 victory. There's a lesson there for designers who are tempted to build the perfect boat for the perfect day's racing, because as everyone in sailing knows, if the wind normally blows at one speed - then come regatta day it will surely blow another.

As a centralised weather data service, however, MDS seems a very logical and sensible step forward from the massed fleet of weather boats seen in previous Cups. At least in this respect the small teams won't be put at a disadvantage compared with the wealthier teams. A small blow for democracy in the far-from-democratic world of the America's Cup.