Sailors are a hearty type, but even hearty bodies get tired, especially when exposed to world-class competition that requires A-game performances for several days in a row. Such is the game at the 2016 Alcatel J/70 World Championship, hosted by St. Francis Yacht Club, as San Francisco Bay has been delivering big wind and waves all week for the 68 boats from 15 countries racing in this high-octane event. Stir in a strong ebb-tide cycle and the Berkeley Circle racing area quickly becomes a small sea of white caps that sap boatspeed and test stamina. “It’s been a tough series for us—we expected that—but it’s been tougher than we thought,” said Simon Ling, skipper of the Corinthian Team RAF Benevolent Fund Spitfire (GBR 123). “Everyone warned us that it was going to be cold and windy, and it has certainly delivered. We like those conditions, but sailing a keelboat in the chop—we haven’t had a lot of experience with that, so that’s all been part of the learning curve this week…It’s been a fantastic event and we are loving it.” While Ling and company enjoyed a strong day four, with a fourth-place finish in Race 9 and a second-place finish in Race 10, their feelings were echoed throughout the fleet. “This morning I woke up and said, ‘It feels like day four,’” said Justin Kromelow, skipper of Loose Lucy (USA 375), who celebrated his 50th birthday on Thursday and boasts the coolest-looking sails in the fleet. The day began innocently enough, with bluebird skies, 4-6 knots of breeze, and a flood tide that kept the racecourse smooth for the run to Berkeley Circle. Then, the air filled to 8-10 knots. Two knots of flood tide escorted the fleet back downhill after rounding the weather mark in 10-15 knots. These conditions suited Brian Keane and his Savasana (USA 96) crew, who took the day’s first bullet. “We got a good start; we got off the line cleanly. We headed to the left side of the course, and we got into the good wind and current,” said Keane, adding, “I like these conditions!” Unfortunately for Savasana and other teams that prefer the cerebral stuff, Mother Nature had other plans, as the breeze continued building and the tide clocked from flood to ebb. Small white caps appeared that grew into deeper troughs and prouder peaks as the tide powered up and the breeze built to 15-18 knots. The Race Committee started Race 9 cleanly, and—come the leeward gate—Douglas Strebel’s Black River Racing (USA 51) was in the lead, followed by Heather Gregg’s Corinthian MUSE (USA 95) and Matías Seguel’s Allegro (CHI 74). Strebel successfully staved off advances from the pack to take the bullet, followed by Joel Ronning’s Catapult (USA 187) and then MUSE. Conditions got serious in Race 10, as the ebbing tide and breeze produced the week’s biggest seas thus far. Outbound water swept enough boats over the line early to warrant a general recall, which in turn inspired the race committee to fly the U flag, meaning that anyone OCS would be disqualified. Unfortunately for Claudia Rossi’s Petite Terrible (ITA 853), who began the day in first, the Race Committee announced her over early; Rossi and company sailed a brilliant race and crossed the line in first place, only to realize their starting-line mistake. Instead, the bullet went to Jud Smith’s Africa (USA 179), followed by Ling’s Team RAF Benevolent Fund Spitfire and Ricardo Brockmann’s Vincitore (MEX 401). Just yesterday, Smith reported that he preferred light-air sailing after taking a bullet in Race 7. “I changed my mind!” said an ebullient Smith. “We had a good start, the breeze was a bit more predictable this afternoon, and we have good speed. We’re good upwind and we’re good in the breeze.” After four days and 10 races, Ronning’s Catapult is topping the leaderboard, followed by Julian Fernandez Neckelmann’s Flojito Y Cooperando (MEX 384) and Carlo Alberini’s Calvi Network (ITL 456). Live tracking is available at http://www.tractrac.com/web/event-page/event_20160926_JWorldsStF/905/. Complete results are available at https://www.regattatoolbox.com/results?eventID=klcyTZvX7U. Photos are posted on the J/70 Facebook page.