Larry Goddard/Pat Caldwell's Oahu Surf Observations These are visual observations made in "Hawaii Scale", which is one-half peak face, trough-to-crest height on the shoreward side of the wave at time of maximum cresting. Format: yyyy mm dd nshor wshor almo dh winw wspd wdir nsd ssd 2000 1 1 8 4 1 2 3 2 17 15 999 2000 1 2 5 2 1 2 2 2 17 15 999 2000 1 3 4 2 1 2 2 2 17 15 999 yyyy: year, mm: month, dd: day nshor (mostly Sunset until > 15 Hawaii scale (Hs), then Waimea reports are used) wshor (Makaha) low quality, use with caution almo (Ala Moana) south shore dh (Diamond Head) winw (Windward Oahu (east side) index) use with caution wspd (wind speed in beaufort for open waters) wdir (wind direction, coded 1=N 2=NNE 3=NE, etc ... 16=NNW 17:calm, 18:mixed) nsd (north shore wave direction as above) ssd (south shore direction) missing data flag 999 Background/Explanation: Data are recorded in Hawaii scale, which has been shown with photographic evidence to be half the trough-to-crest height at the moment of maximum cresting for the highest portion of the shoreward wave front, with a 20% margin of error (Caldwell and Aucan, 2007). Important references: Caldwell, P.C., 2005. The Validity of North Shore Oahu, Hawaiian Islands, Surf Observations. Journal of Coastal Research, 21(6),pp. 1127-1138. Caldwell, P.C. and J.P. Aucan, 2007. An Empirical Method for Estimating Surf Heights from Deep Water Significant Wave Heights and Peak Periods in Coastal Zones with Narrow Shelves, Steep Bottom Slopes, and High Refraction. Journal of Coastal Research, 23(6). This dataset includes daily estimates of surf size at the various sides of Oahu, Hawaii. Since it is visually acquired, readings were only made during daylight hours. The data represent the upper end of the reported range for the highest report for any given day. For instance, if the surf report was 4-6 in the AM and 2-4 in the PM, 6 would be recorded. The height nominally represents the average of the highest 10% (H1/10) waves, which are the common though less frequent higher sets with such groups arriving roughly 8-15 minutes apart. Mr. Larry Goddard provided the database for the North Shore from 1968-9/1987 and the south shore (Ala Moana) from 1972-7/1987. Many observations were his own, but he also received help from reputable surfers such as Randy Rarick, Peter Cole, Bernie Baker, and Lt. Benson. Mr. Caldwell began a digital archive of surf observations, coincidently, when Mr. Goddard moved to the mainland and discontinued his set. The Caldwell set from 1987 onward considers the primary source as the Oahu lifeguard and the Surf News Network reports, unless more reliable information was provided via a network of surfing friends. The data quality should be higher starting in 1999 due to the availability of Internet cameras at key surf locations. For the North Shore, Sunset Beach is the primary observation spot when the surf is below 15 Hs. Sometimes for a straight north to northeast swell, Laniakea is used if available since it could be bigger than Sunset. Once the surf is 15 Hs or higher, Waimea Bay is the typical observation point. For North Shore climatology, note AUCAN paper below. To translate from Hawaii scale to trough-to-crest for heights greater than 15 Hs, zones of high refraction on outer reefs are double Hawaii scale within a 20% margin of error. Heights at Waimea are roughly 1.5 times Hawaii scale. The wave direction data began in 1990 based on personal knowledge of Mr. Patrick Caldwell, who has studied the weather maps daily in preparation of surf forecasts. Another technique used was noting the swell sizes on the various sides of the island. For instance, if Makaha is 8', Sunset is 10', and N.Beach is 2', then the direction is obviously dominated by NW component. Since 12/2001, a directional buoy near Waimea, Oahu has improved the wave direction information. For the Windward Surf Index, reports from North Beach on the Kaneohe Marine Corp Base Hawaii were used until 1995 when it was discontinued by the Oahu lifeguard reporting system. Since then, Makapuu has been the primary reporting site, although Mr. Caldwell lives in Kailua Hawaii and has been able to fine tune the estimates personally. The windward index includes both trade wind energy as well as any long period swell from North Pacific sources. Due to potential for large gradients in size along the windward coast during the arrival of long period energy, especially if the direction requires refraction around Kahuku Point, the Windward Surf Index is of low quality. However, by correlating the wind to the waves and using only trade events, the data are likely of reasonable quality. For understanding wind wave energy, see Aucan, J., 2006. Directional Wave Climatology for the Hawaiian Islands from Buoy Data and the Influence of ENSO on Extreme Wave Events from Model Hindcast. 9th International Workshop on Wave Hindcasting and Forecasting. JCOMM Technical Report No. 34 / WMO-TD. No. 1368. Wind data are an estimate of ballpark open ocean speeds, independent of island influence. Usually, the Bellows or Kahuku anemometers are used during trade wind events. For a south shore surf climatology, see Caldwell, P.C., 2007. Spectral Density Composites for Aid in South Swell Forecasts for Oahu, Hawaii. 10th International Workshop on Wave Hindcasting and Forecasting, Turtle Bay, Oahu, Nov. 11-16, 2007. A new climatology has been made and is available at http://ilikai.soest.hawaii.edu/HILO/climo/oahu_surf_climatlogy.html For other surf research, see: http://ilikai.soest.hawaii.edu/HILO/SurfResearch.html