Tuesday, July 21, 2015

ACWS Portsmouth.....a look at the course area

The Americas Cup World Series 2015 starts in Portsmouth with 4 races that count in a fairly complex longer term scoring system. There will be another 2 events (Gothenburg and Bermuda) in 2015 and possibly 6 events next year,  before the AC45Fs are put away and the AC48s are used in the Louis Vuitton Qualifying Series.
These boats are fast and furious gone are the hydraulics and back is full physicality of getting the foils, sails in out up and down with pure man power. Then put 6 boats next to each other and confine them to a race area  that is not much bigger than a square nautical mile within spitting distance of the shoreline and you are sure to get a spectacular display of racing in high end machines at the highest level
Here, we take a look at the course area and what other interesting things the sailors maybe needing to consider outside of just trying to sail these wild machines!

First up the course area. They have publicised the proposed course area and the courses for the forthcoming weekend based on the historical average of a SW wind.
Two courses are proposed either 5 or 7 legs with a short reach to the finish along the shoreline for the spectators. But what is new is a reaching start in the middle of what is essentially aiming to be a windward-leeward course - there is most certainly going to be a lot of action as the boats accelerate towards each other and turning marks in fairly rapid succession. Good luck umpires!

Let's take a closer look at the course area and how the course might swing if the wind is not a SW....which my sources currently say is highly likely.
The black line shows the proposed course area for a SW wind the dashed line is a suggested area within which they will try and swing this windward-leeward keep in mind though they want to somehow finish along the spectator shoreline.
The course area in theory will always be restricted to a rectangular box around the windward-leeward to allow for spectators to get a good view and inevitably limiting where the AC45F can go keeping them closer together.

Taking a closer look at the chart there are a couple of interesting features about the course area. First of all the clear inclusion of Spit Sands Fort in the middle of the course area...surely the best place to really watch the racing from - you will most certainly feel like you can touch the boats from there. Also, there will definitely be some layline avoidance or judging to not be aiming for the fort. We all know what these things can be like........MAGNETS!
Then if you look at the red dotted line theses mark areas of notably shallower water. All races will be carried out on a rising tide (HW Portsmouth 1747 Fri to 1946 Sun) so lack of water will not be a problem with shallowest water being over these areas at 4.0M. However, it does mean that the tidal flow in the area is not all that straight forward. Fortunately, we are heading into neaps so it is unlikely that we will see anymore that 0.8KT in tidal strength across the course and this will be in the S and W of the course areas.
None-the-less it is likely to effect laylines, startlines and every 0.1KT matters so for interest below is a rough idea of how the tide will be moving in the proposed racing periods.

The question now is what will the wind be doing? Pop back tomorrow to see an outlook for the upcoming ACWS Portsmouth event or find me on twitter (@LibbyGreenhalgh) and instagram (@Greenhalghweather)