The high tide is normally going to be up to about the top of the first course of stones. Certain very high tides, only a few times a year, will be another couple of feet higher. The "mean higher high" as it were... that'll be about halfway up the bulkhead or a little more.
The total tidal range runs about 16 feet from extreme to extreme. The lowest low tide is about -3.5ft and the highest high tide is about 12.5 to 13ft. Most days are not that extreme and run about 10 to 12ft total range.
But I can confirm that the time, and the tide, does in fact wait for no man. I've tested this.