Cowes Week navigation tips part 1

Jim Saltonstall looks at the winds and tides in the eastern Solent

East Solent (south)
Wind Direction

0-70 degrees: This is a relatively clear wind sector for this part of the Solent. Blowing from the flat mainland some distance to the north, you ought to get a reasonably steady breeze from this sector. But this breeze will also create the roughest sea state, with a lot of backwash off the land, and the quickly shallowing ledge jutting out from the island. Because you are sailing from shallow water into deep water, the tidal wind shift will be an important part of your strategy.

70-140 degrees: Another relatively clear wind sector for this race area, with the breeze blowing more or less straight up the Solent. But there is almost always likely to be better wind further offshore from the island, with the wind anywhere in this sector. That is because with the wind at 70 degrees, the mainland shore is a convergent wind shoreline and with the wind at 140 degrees the island is a divergent wind shore-line - in both instances there will be more wind to the north. And at any angle with the wind blowing onto the island shore, it's likely to be pushing the breeze up to create a wind shadow - still indicating more breeze to the north.

140 degrees: With the island now very definitely a divergent wind shore-line, it's clear that there will be less wind within half a mile of the beach. So for breeze, head left upwind. Unfortunately, if the tide is ebbing against you, the left will be the worse place for tide - a classic Solent tide versus wind dilemma. There is no good rule for this situation - the only way to be sure is to test the beat with another boat prior to the start. But if you have to make an off-the-cuff decision, remember that the tidal effect is always there, while the wind effects are less reliable. If, however, the tide is running with you upwind, you can expect boat speed to be king on a one way race track.

140-180 degrees: With the wind blowing offshore you can expect it to be shifty. As with any offshore wind, the shifts are over a narrower arc and less frequent in the starting area, more frequent and over a wider arc at the top mark. It's also important to remember that all the upwind legs with the wind in this sector will be going from strong tide into weak tide, and the tidal wind shift should not be forgotten.

180-240 degrees: Once again the wind is offshore and the shifts will dominate. From this sector the wind likes to line up with the valleys running down to the Solent from inland. That means we start to see good port tack lift puffs along the shore. But beware, as the land that backs this part of the Solent (particularly towards the western end of the race area) is quite high, and the breeze can be soft inshore.

240-270 degrees: The eastern part of the race course sees the island shore becoming a convergent shoreline, and you can expect more breeze here. This is not true of the more north-to-south facing shoreline to the west of the race area, where the breeze direction is more controlled by the puffs and shifts coming down from the valleys and over the headlands. There are always good port tack lift puffs up this shore, but it's a difficult transition to manage between these two zones. A particular danger is if you have to round the mark west of Old Castle Point by East Cowes. In this case you must be careful not to get sucked right up into Osborne Bay. This is a notorious spot, and the big port tack lifts that role off this shore-line can suck you into one of the most airless black holes on the Solent.

270-360 degrees: The whole of the island shore-line has now become a convergent wind shore, and should have better breeze than offshore. It is also possible for the band of strong wind blowing out of Southampton Water to carry all the way down the eastern Solent, and the combination of both effects usually means good breeze across the whole race course. The exception is just to the east of Old Castle Point in a proper westerly, when the breeze is light and shifty under the land.