Higher High Water (HHW) 2 : The higher of the two high waters of any tidal day. The single high water occurring daily during periods when the tide is diurnal is considered to be a higher high water. See: Figure A-10
Intergovernmental Oceanographic Commission IOC technical series 37, Tsunami Glossary (A glossary of terms and acronyms used in the tsunami literature - English), , United Nations Educational, Scientific and Cultural Organization UNESCO, Paris, France 1991. http://unesdoc.unesco.org/images/0008/000885/08853 8eb.pdf, (ND/ Tsunami Sci - Brit) {590}