Robin Hewitt, veteran sailor, multiple Melbourne Osaka Cup competitor and skipper of the well know yacht Yoko, wrote the featured article in our Newsletter last week called “It’s all about the Weather”. We thought that it was certainly worth posting here on the site as well.
The Melbourne to Osaka Double Handed Yacht Race is unique because it crosses the weather climate systems of the world. It starts in mid March from Melbourne in the ‘autumn westerlies’ wind belt.
Next as the yachts move north, they must cross through the center of the southern belt of high pressure systems, with predominantly light winds or calms. Here there are two strategies possible: aim for ocean eddies and currents for a lift north, or gamble on coastal breezes by sticking close to shore in order to hopefully avoid the eastern Australian south flowing current. For skippers, these are individual decisions requiring knowledge of your boat and its performance characteristics, combined with a personal interpretation of the current weather situation. Hopefully, the cyclone zone of Latitude 20 deg. to 10 deg. south is quiescent.
After breaking out of the light weather, the equatorward side of the highs gives rise to the south-east trade winds and glorious spinnaker runs until meeting the Inter Tropical Convergence Zone. The ITCZ, affectionately nicknamed The Doldrums, is known for its light winds and calms. It lies roughly in the area around the Solomon Seas and yachts must also squeeze through the ‘Gate’ between the Islands – in itself a navigational challenge.
In the tropical areas, convection storms plague the yachts with blasts of high winds, generating tactical challenges in order to produce the best directional gains. Alongside these difficulties, battling exhaustion tests the sailors further. Judging ocean currents and wind effects are further decision points in this area, perhaps illustrated by New Ireland, a narrow, razor backed, yet very high island with many influences. Also there is the Northern Typhoon area between 10deg and 20deg N. Breaking through this frustrating zone, yachts in the Melbourne Osaka Cup then enter the southern side of the northern high pressure belt, otherwise known as the north-east trades. Here the miles soon mount and the passage to Japan quickens, with a series of tremendous daily runs before once again having to get through the light winds of these high pressure systems’ centers.
It’s now time to prepare for the strategic approach to Japan in the fringe of the northern westerlies zone. By now the much fabled North Pole Star will have been visible in the night sky for some time. Usually somewhere around here, a vigorous low pressure system will bring strong winds and for southern hemisphere sailors, the weather systems now operate in the opposite directions requiring interpretation skills and unusual (to them) weather planning.Japan lies not only in the fringe of the northern westerlies, but its weather is highly influenced by the continental land mass of Asia and Siberia particularly. In addition it has its own version of the East-Australian Current, the Kuroshio, which has to be negotiated carefully in order not to be swept away from Osaka.
Fortunately, the Japanese weather bureau produces excellent information and mapping to enable good decision making. Negotiating a crowded shipping route to Osaka Bay brings the final challenge of traversing an area filled with vessels of all kinds and differing shorelines unusual to first time visitors. Winds here can be strong but more usually very light and the finish is near a river mouth, which after heavy rain can result in adverse currents requiring persistence and determination. So close to finishing, after so long at sea and so many obstacles!
The elation of accomplishment and the wonderful welcome at Osaka Hokko Yacht Club is the pinnacle. Good luck to all competing in the 2018 ‘Yachtsmans Everest’.
– Robin Hewitt