With no gradient wind, A and B are enjoying the sea breeze induced by a large island on a sunny day. A experiences less breeze as she moves in the tide. B is moved against the breeze and so feels more wind. Both boats will notice a difference when the tide turns. Wind and tide will have a considerable impact on sea conditions. Wind and tide directly opposed (wind over tide) can produce big waves with breaking tops, particularly in the entrance to an estuary mouth or over a sandbar. It pays to refer to an almanac or ask locally what conditions are likely.