Cowes Week - Insights from Rupert Holmes on tidal heights and streams

by Cowes Week Ltd on 15 Jul 2014 Tides for this year’s Aberdeen Asset Management Cowes Week are predominately neaps, so streams are relatively weak in Solent terms. However, they will still play the most critical function in any race winning strategy, and will are likely to play a big factor in the start of races from the Royal Yacht Squadron line as the regatta progresses. In addition, on a number of days the starts will be close to low water.

On the opening day low water is just over an hour and a half before the first start, so the stream will be east-going for the entire start sequence. However, as the week progresses and low water moves progressively later, the eddies close inshore will become ever more important for boats starting to the west on the Royal Yacht Squadron line.

These start to form as much as three hours before the main stream changes direction, roughly one hour before the time of local low and high water. Initially the eddy is very close inshore off the Green, but it moves into a wider band and extends further along the shore towards to the time at which the main stream changes direction. As well as studying the best tidal information you can get, looking for tide lines on the water which indicate the border between the main stream and the eddy flowing in the opposite direction.

However, it’s worth sounding a couple of notes of caution at this stage. Firstly, don’t be tempted to go so far inshore in search of favourable tide that you risk running out of wind in the lee of the shore. To avoid this keep a sharp eye open for the maximum extent of the calm patches on the water.

Given that at some point in the week all boats starting on the RYS line will do so at low water, it’s also important to watch for Grantham Rocks, a little to the west of the start line, and the rocks inshore towards Gurnard Bay. These always seem to catch a few competitors in years when the start times are near low water.