SAN FRANCISCO -- On the day that New Zealand had the chance to wrest the America's Cup from Oracle Team USA and take it back to Auckland, heavy winds and strong tides forced the postponement of Tuesday's races.

Also Tuesday, boat designers from both teams suggested that the days of monohull sailing are over for the America's Cup after the excitement seen this week with the 72-foot, hydrofoiling catamarans.

"We've taken a 2-D sport and turned it into a 3-D sport," Nick Holroyd, the technical director of Emirates Team New Zealand, told reporters.

Races 11 and 12 are expected to be contested Wednesday afternoon, when winds are forecast to be lighter. New Zealand, leading 7-1, needs two more victories to win the America's Cup. Oracle Team USA, owned by software billionaire Larry Ellison, needs eight.

The cancellations were met with mixed emotions by New Zealand fans.

"We're a little disappointed we didn't see the last race, but for the sake of New Zealand, we're glad it was canceled," said Dianne Dearlove, 62, who was booked on a flight home to Auckland on Tuesday night.

Oracle Team USA has shown over the past week that it performs better in heavier winds.

"That's where Oracle's speed comes from," said Paul Donegan, 57, from Auckland. "From a patriotic point of view, we go better in lighter winds."

Crews from both boats seemed eager to get on the water, telling fans at America's Cup Park they were ready to go. But strict wind limits were imposed after a crewman from Sweden's Artemis Racing team was killed when the boat capsized during a training run last spring.

Those limits came into play Tuesday as winds built past 25 knots, or more than 28 mph. The strongest ebb tide of the year was also pulling water under the Golden Gate Bridge and out of the bay, causing especially rough water. Similar conditions were a factor in the capsize of Oracle Team USA last October during a training exercise that nearly destroyed the boat.

Oracle Team USA has made several improvements to its 72-foot catamaran over the past week that have increased boat speed, particularly upwind. Over the weekend, the Americans won Races 8 and 9, then lost Race 10, in some of the most exciting racing the America's Cup has seen in its 162-year history. On one leg alone during Race 10, the lead changed an unprecedented four times.

Boat designers from each team told reporters that the excitement of the past week should solidify the future of America's Cup racing in foiling catamarans instead of monohulls. Although many sailing purists long for a return to the graceful monohulls, Oracle Team USA designer Dirk Kramer said, "Something similar to this is definitely in the future," adding, "Undoubtedly they'll get a bit smaller" and it's imperative the costs go down to encourage more teams to join.

But the decision will be made by the winning team, along with its challenger of record. If the Kiwis win, the challenger would be Italy's Luna Rossa Challenge.

"Just how good the racing is this week makes it really, really difficult to go past this style of racing," Holroyd said. "From a technical standpoint, these boats are phenomenal."

Contact Julia Prodis Sulek at 408-278-3409.

34TH AMERICA'S CUP

Emirates Team New Zealand 7 points,
Oracle Team USA 1 point

Best-of-17 series or first team to 9 points
Wednesday: Races 11 and 12, 1:15 p.m. and 2:15 p.m. 1 p.m. on COZI-TV
Thursday: Races 13* and 14*, 1:15 p.m. and 2:15 p.m. 12:30 p.m. on NBC Sports Network, 1 p.m. on KNTV
Friday: Races 15* and 16*, 1:15 p.m. and 2:15 p.m. TV TBA
Saturday: Races 17* and 18*, 1:15 p.m. and 2:15 p.m. 12:30 p.m. on NBC Sports Network
Sunday: Race 19*, 1:15 p.m. TV TBA
* -- if necessary
NOTE: Because of penalties, Oracle Team USA began the America's Cup with minus-2 points, meaning it needs to win 11 races to retain the America's Cup. New Zealand needs to win nine.
COZI-TV can be found on Comcast Channel 186 and over the air on Digital Channel 11.2.