The wind's ahead
i.e., blows in the direction towards which the ship's head points; in front. If the wind blows in the opposite direction (i.e., towards the stern) it is said to be astern. When one ship is ahead of another, it is before it, or further advanced. “Ahead of his class,” means at the head. Ahead in a race, means before the rest of the runners.
To go ahead
is to go on without hesitation, as a ship runs ahead of another.