How to read wave/swell buoys?

It means peak-to-peak, but I don’t know the distance at which the buoys are placed, so I don’t know how to calculate the distance from the frequency.

With just one bouy, if it is moving every three seconds, the seas are pretty fast. The frequency would be three seconds . . . and pdworkin is right, it would be the distance between the peaks of the waves.

Thanks! So, it indicates the time between swell pulses. Does it have anything to do with swell size? i.e. if the swell is larger, could you assume the period will be longer because the buoys are moving higher?

@brassman you cannot assume the period will be longer due to the amplitude(swell?) , as they are independent of each other.