The Gulf Stream usually refers to the warm oceanic surface current that originates from the Gulf of Mexico and flows along the eastern coast of the United States as well as Canada and eventually moves towards the middle of the Atlantic ocean.
The speed of this warm water current is drastically very high, which is roughly about 30 million cubic meters per unit second, flowing through the straits of Florida.
If a raft is tried to drift on these currents of Gulf Stream right from the Florida coast, then the raft will be carried forward at a tremendously faster speed and it will eventually reach the middle of the Atlantic ocean.
There is one other, much simpler word, that has a similar meaning: height.
Altitude is a vertical measure, from some point of reference such as sea level on Earth.
So for example when we say that the plain is flying at 10 000 meters of altitude, it's flying 10 000 meters above the mean sea level, but in fact if could be flying as low as 3000 meters above the ground if it's flying above the mountains!
C. Weak winds that blow for short periods of time over small distances
Explanation: For a wave to effectively be produced there need to be large wind, long period of time and a large distance of water. If they are all reduced, then there would be a reduction in the intensity of the wave.