Quartering the seas is a way of changing the direction of your boat relevant to the direction of the wind and waves to improve safety and performance.
You need to remember that WIND OVER WATER MAKES WAVES.
It is the direction of the wind that determines the direction of the waves.
Factors that determine the size of the waves are:
 | The strength of the wind. |
| The amount of time the wind has been blowing in the same direction. |
| The contours of the seabed. (As the water shallows it forces the waves up, making them bigger and eventually causing them to break. You will see this on the beach or foreshore and when waves hit rock outcrops.) |
| The land masses around the water. (As when waves are forced between islands or through narrow channels.) |
| The fetch. (That is the distance of water the wind has travelled over before it gets to your position.) |
| And the other power force effecting the waves is the TIDE. |
With the wind and tide travelling in the same direction, the waves (although large) will tend to be more rounded. With the wind against the tide, the waves will tend to 'stand-up' more and be shorter and sharper, making the conditions more dangerous.
All these conditions should be taken into consideration when planning your trip out on the water.
When heading into the waves, you should trim the bow down so the waves do not wedge up under the bow causing uncomfortable pounding. Bow down allows the flare of the bow to throw the water out and away from the boat.
With a following sea (with the wind and waves behind you), you should trim the bow up to stop it burying into the wave troughs.
To improve the comfort and safety of the ride, you could 1/4 the seas. When heading into the waves, the bow is pounding straight into the face of the waves, causing the boat to impact hard. You risk damaging the hull and injuring your passengers. If you turn the boat slightly, the bow will slice at an angle to the face of the wave and make for a softer ride.
DO NOT TURN TOO SIDE ON TO THE FACE OF THE WAVE WHEN THE SEAS ARE LARGE.
With a following sea, you can angle the boat so that the waves hit more on the aft quarter (back corner) of your vessel. This will reduce the likelihood of your vessel being forced underwater in the trough or into the back of the wave in front of you.
DO NOT TURN YOUR BOAT TOO SIDE-ON AS YOU CAN BROACH THE BOAT
Broaching is when the wave force hits the side of your vessel and can then spin you full side-on to the face of the wave and flip your boat. If you feel your boat starting to broach, try to power on and turn back down the wave to come back onto your quartering position.
NEVER TRAVEL AT FULL OPEN THROTTLE
You should always leave a little power in reserve for emergencies like this. You will also use more fuel if you use full open throttle all the time and unnecessarily strain the motor.
In a following sea, the safest place to have your boat is on the BACK of a wave. Should you need to turn - do it on the BACK of a wave.
PLEASE NOTE: This is only theory and you will need to learn how your boat handles in different sea conditions and with different loads on board. This is a guide only and aimed at planing ( non-displacement) hull vessels.
