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Sydney to Hobart: Sailing to win
Playing the weather can make a big difference in this quick ocean dash along Australia’s south-east coast. Severe weather forecaster and ocean racing navigator Kenn Batt tells us why ... Synoptic brief: 2) Bass Strait: Is a frontal change looming? Can you sail west early in order to ease sheets later? But be careful of getting sucked too far into the strait. Otherwise, ease sheets early and sail east of your rhumb line to avoid light airs later. 3) East Coast of Tasmania: Beware of light airs in the lee of Tasmania's central highlands, especially after a front has blown through. 4) Up the Derwent: How many races have been won and lost in this last 10 mile stretch? When the going gets tough: Re-living the bomb of 1998. No guts, no glory Since the great storm of 1998, the Sydney to Hobart yacht race has attracted renewed interest, despite the tragedy and drama of that event. With this year’s race counting as a competitive leg in the Volvo Around The World, a highlight of the 630 nautical mile dash down the east coast of Australia will be a battle between Volvo 60s: Vessels designed for downwind flying. That fact alone will make this year’s race one to watch, because historically the Sydney to Hobart features little downwind flying. 1999 was an exception, and the ex-Whitbread 60 Swedish Match, renamed Nokia, broke the race record as persistent north east winds, the result of a stalled high to the south east and a developing trough to the west, delivered beautiful surfing conditions to fleet leaders. In 2000 it was all upwind after the first front hit the fleet near Eden, with Swedish Maxi Nicorette claiming line honours and the little 12m Farr 40 Ausmaid claiming the race on handicap. According to Kenn Batt, Sydney severe weather forecaster, and experienced navigator on numerous Sydney to Hobart races, persistent north east winds are the exception, rather than the norm. However, the Volvo 60s can handle an upwind bash. Like their smaller cousin Ausmaid - from the same design firm as most of the Volvo competitors - these boats are a world away from the light downwind sleds built to break the Hobart race record. Last year five Volvo 60s - all second-hand boats from the last Whitbread campaign - finished in places three through seven right behind Nicorette and Melbourne maxi Wildthing. Leading the Volvo 60 pack was the German entry Illbruck, skippered by John Kostecki, just 40 minutes behind Wildthing, which says something about how well these Open 60s can handle a range of race conditions. The entire Volvo 60 fleet finished within 16 hours of each other and the first two were just 47 minutes apart after almost three days of racing.
The first half of the race is devoted to getting south as fast as possible, and one ticket to that destination is to hitch a ride on the southbound East Australian Current. Current which runs at its strongest on the continental shelf, just 20 miles offshore, can exceed three knots and that little amount can make a big difference to the competition. If the race is ‘cut and dried’ and a north-east seabreeze persists, skippers will take advantage of that fast-flowing southerly current. But, like many gifts, it comes at a price. A typical summer feature along the south-east Australian coast is the ‘southerly buster’ in which blustery winds behind a frontal change move up the coast from the south, rather than across the continent from the west. You can thank the 2000m high peaks in the great dividing range for contributing to this effect. With depressions below 40 degrees south moving past the continent every three or so days, yachts in the Sydney to Hobart are likely to get hammered by a buster at some point. And, if it comes early in the race, while yachts are catching southbound current offshore, that blustery wind - coming in at 30 to 40 knots plus - will push against the three knot current creating steep, ‘back-less’ waves. Add to this equation a lightweight, competitive race boat beating to windward and the result can be damaging indeed. Batt points out that in 1997, while navigating aboard Nicorette, (a former Whitbread veteran which sailed under the name Charles Jourdain) a southerly change created waves steep enough to break two and a half frames in the bow of this 60 foot boat. The subsequent eight hours spent dockside at Eden effectively ruined their chances for line honours. And yes, they were well positioned - ahead of consistent front runner Brindabella - before the boat suffered damage.
If a frontal change is forecast, Batt suggests sailing on a rhumb line between Gabo Island and Tasman Island or just to its west. That way, when the westerly change blows through, skippers can ease sheets a little and still keep racing at full speed southwards. However, navigators beware: Between Montague Island off Narooma and Gabo Island at the entrance to Bass Strait, the continental shelf comes in quite close, and here the current can move at its quickest. Navigators have to monitor their boat’s progress carefully, because there is the very real chance that as the current enters Bass Strait it will swing to the west, carrying yachts with it. With very little warning navigators could find themselves deep in the strait. At this point the seabed becomes shallow, and in a westerly blow the sea state can be just awful. If no frontal change is imminent, Batt says it is important to get as far south as fast as possible once racing yachts are in Bass Strait. If this means easing the sheets a little and sailing east of the rhumb line between Gabo Island and Tasman Island, so be it. Average weather conditions dictate that a south-east wind will fill in before yachts sail too far down the east coast of Tasmania, and they will then have a favourable slant into the mouth of the Derwent River. The other advantage of easing sheets and sailing east of the rhumb line, is that it puts boats well offshore, especially south of the Freycinet Peninsula, an area notorious for producing meso lows and lee troughs in the west to southwest flow which eventuates after a cold front has gone through the region. Batt says these meso lows and troughs, or localised zones of weak low pressure are the result of Tasmania’s 1500m central highlands. These peaks effectively shear the prevailing westerly wind flow, producing light and variable winds on the surface, downwind of the coast for a distance of some 30 to 50 nautical miles offshore.. Bat understands this portion of the coast, having bogged there while navigating Ragamuffin in 1995. "That was the year we broke the rule and went in close to the Tassie coast chasing a land breeze overnight," he recalled. "By about 6 or 7am the wind dropped out entirely. We had to wait for a sea breeze to develop, which went quickly east, then south. As we sailed further towards the Derwent the wind came southwest and freshened. Before we lost our wind we were way ahead on handicap and we lost the race right there." This converted Open 60, renamed Xena, will use water ballast (now allowed in Sydney to Hobart contenders) to good effect if downwind conditions persist - but if the race chances across a southerly buster delivering headwinds and steep seas, don't expect life on board this warrior princess to be any fun at all! picture © Roy Haverkamp. Of course, many races have been won or lost in the Derwent River, only a few miles from the finish. According to Batt the Derwent is the next most troublesome portion of the race behind Tasmania’s east coast. Typically the seabreeze dies away in the evening and a weak land breeze replaces it as night falls - about 9 to 10pm in summer. But with strong ‘synoptic forcing’ or a strong weather system close to Tasmania, winds can blow all night making the job of getting up the Derwent a lot easier. Unfortunately, in the lighter wind regime, there is little a skipper and navigator can do so late in the game except wait for wind. "The worst part of it all is to watch the yachts astern catch you in the first good puffs of wind to arrive around dawn," Batt says.
What makes the Sydney to Hobart especially attractive is the very real chance that bad weather will knock the fleet on its butt. In 1993, Batt was navigating on Wild Oats (the eventual IOR winner on handicap), when an east coast low developed in eastern Bass Strait, driving southerly winds onto the fleet. With strong wind pushing against the east coast current, big and damaging waves were the result. To compound the problem, this storm refused to move east - like they are ‘supposed’ to do, tracking due south instead, increasing the wave energy and forcing two thirds of the fleet to pull out. Wild Oats sailed well east of the rhumb line, and Batt only managed to save the boat’s winning position by picking two short bursts of south east winds within the southerly flow, and urged the crew to tack in towards the coast. During that race Wild Oats actually sailed into the centre of the low pressure cell, and Batt described conditions as ‘eerie’ when winds went from 50 knots to nothing. The boat sailed in circles before hitting the other side of the vortex and experienced the violent return of those storm force winds. Throughout the ordeal the seas averaged eight to 10 metres. Of course, the 1998 race was the worst in its history. Three elements contribute to that disaster, in which six people died: An ex-tropical cyclone off Lord Howe Island tracking south, a stalled high south east of Tasmania preventing the normal west to east flow of weather and a strong low developing in the Australian Bight and moving east. Both the ex-tropical storm moving south and the developing low traveling east pushed up against the blocked high. As they came together, isobars surrounding the three systems packed tightly together and intense pressure gradients were the result. When the developing low in the bight moved into Bass Strait it absorbed the intense tropical moisture funneling clockwise around the ex-cyclone and the cool, moist oceanic air swirling anti-clockwise around the stalled high. The result was a meteorological bomb or explosive cyclogenesis and the Sydney to Hobart fleet was right underneath when it happened. As Kenn Batt also points out: The north-east wave train produced by the ex-tropical low traveled with the east Australian current and met new waves produced by storm-force southwesterly winds in Bass Strait. The seas that combination produced were horrendous - backless, and massive. Survival was the order of the day, and despite experience and training many were unprepared. "The area in northeastern Bass Strait, around Gabo Island, from an oceanographic point-of-view, can become quite complex," says Batt. That storm resulted in a coronial inquiry, investigations and accusations. Authors the world over wrote books on the subject and web pages are devoted to it. The result? More quality entries into the Sydney to Hobart race than ever before. Kenn Batt has sailed in seven Sydney to Hobart races. This year, like last year, he will be in Hobart working as forecaster/liasion officer attached to the Hobart race management committee. Did you know? Local geography affects wind flow along the east coast of Tasmania, where the central highlands actually shear westerly winds, the prevailing direction following a cold front. This shearing effect creates a ‘meso low’ or zone of light winds along the coast especially between Freycinet Peninsula and Tasman Island extending 30 to 50 miles offshore. This is particularly so off Maria Island. In the vicinity of Gabo Island, a ‘bubble high’ can appear after a cold front, and skippers expecting south west winds in the wake of the front, can be surprised to find north east winds in their place. This is because the sub tropical high can extend a ridge over this south eastern corner of the continent, creating the ‘bubble high’ and affecting prevailing winds. In the Sydney to Coffs Harbour race, which starts on January 2, larger scale weather issues are relatively less important most of the time. But local-scale winds, such as the sea and land breeze, become most important. Kenn Batt says the state of the east Australian current is quite a major factor because yachts are forced in against the coast as they head north., to avoid its southerly flow. This is especially so off Sugarloaf Point and Port Macquarie where the current washes into the coast. Skippers and navigators try to use coastal features which create eddies in the current to hitch rides northwards. Batt points out that the transition between the daytime seabreeze and the nighttime land breeze and vice versa becomes critical when yachts are so close to the coast. It can really test the mettle of even the very best skipper or tactician/navigator. More great reading! Understand and follow the progress of the Volvo Ocean Race. Follow the progress of Sydney to Hobart 2001! The Tasmanian government also has a web site for the great race. The Australian Bureau of Meteorology has released an in-depth report on the 1998 Sydney to Hobart race and the storm that killed six sailors. Weather router Roger Badham talks ocean tactics in general, and relates a few Sydney to Hobart race tips.
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