Wind spotting
In light airs, wind is king – so if you spot any, head for it! Wind appears on the water as dark patches of cat’s paws, and is usually easy enough to see. It’s also worth heading for any large cloud formations as there is often more wind under the clouds.
The biggest wind differences to be found on a sunny, light-wind day come with sea breezes. It’s worth getting to know the signs of a sea breeze and positioning yourself correctly to pick it up first. Recently, we were motoring east across Lyme Bay, and noticed large cumulus clouds over the land. It was the hottest day of the year, and the clouds were forming in a clear blue sky – perfect sea breeze weather.
Sea breezes tend to form first in a zone extending up to a mile offshore, rolling out thereafter like a carpet – so it follows that if you want to get the wind first, position yourself under a mile offshore. Signs that a sea breeze is imminent include puffy cumulus clouds over the land, light airs in the morning, a hot day and a clear blue sky. They don’t always form: in easterly gradient winds on the South Coast they rarely manifest as you might expect given the presence of cumulus.
Wind shear
One odd phenomenon sometimes experienced in light airs is that of wind shear: this is where the wind at the masthead and the wind at the waterline are doing different things. It can make it very hard to set the sails correctly, and may be baffling at the time, but you can adjust the sails to suit. If the wind is further aft at the masthead than at sea level (you’ll know this is happening because the lower telltales will be stalling or the jib backing, while the upper ones are drawing fine), you can induce plenty of twist in the jib by moving the car fully aft and sheeting in.
Alternatively, if the wind higher up is further forward than that at sea level, you can compensate by pulling the car forward and sheeting the leech down harder than you otherwise would.
Helming upwind in wind shear is tricky, but you’ll find it best to helm somewhere between the two wind directions – bearing away a few degrees should help to keep the speed up, and you can experiment to find the best compromise between the two breezes.