That makes sense. If you have 5' of water clearance you should be ok in anything short of a named storm.
We lived in Oriental, NC on Pamlico Sound for 5 years and I became very sensitive to storm surge. Last year the tide hit 4+ feet above normal with just a routine storm. The various hurricanes that hit over the last ten years: Irene, Isabell and Ophelia pushed it to 7-9' above mean water level. A heavy nor'easter could push it to 5' though.