Does the speed of the ship affect the pitch and yaw?

This is indeed true. The yawing (rolling) of the ship is affected by the surface of the wave touching the hull of the ship. If a wave top is under the ship the buoyancy is less, the stability is diminished and the vessel is more prone to roll. When the ship is on a wave trough more of the wave surface is in contact with the ship, increasing stability and reducing the effects of rolling. If the speed of the vessel is almost the same as that of the waves, and in the same direction, the time on a wave top is long and the decreased stability is significant. The chance of this happening is slight as our ship has a length of more than 200 meters and there are several wave tops and troughs in contact with the ship at all times. As for pitching, if the ship has a high speed it may ride down one wave and “crash” into the next. When the ship has a slower speed it will gently ride down one wave and climb the next one.