Of course it is a lot less noticeable at sea, but I find it interesting that in off shore racing yachts we recognise there is sufficient gradient even between the boom and the top of the mast that it is worthwhile changing the shape of the sail to accomodate the wind direction and strength not being unifrom over the whole sail area.
While talking about the sea it is also worthwhile remembering what a signficant effect the sea can have. The onset of sea breezes in the morning and their reversal in the evening has a significant bearing for a surprisingly large distance in land which means winds will be very different both during the day and at night for any airport that is influenced by sea breezes.