How the Surf News Network determines surf height
This is an explanation by Gary Kewley of the Surf News Network, on their surf height determination:
MOST SURFERS ON THE WORLD TOUR AND HERE GIVE HAWAIIAN OR LOCAL SCALE WHICH approximates the open ocean swells.
When these refract and shoal they can double in size. HI surfers scale factually consistent over 4 decades. We at SNN also havent changed in 35 years of reporting. the 'range' is 2/3rds to 50% of crest to trough. or EG 12 faces will be 'called' 5-7' ....or 18' will be called 10' local. A 7' face is 4' local. with the amazing variabitity of waves and spots its sensible to have error/respect bars of 10-20% ...to claim exactitude is naive but surfers do try! :)
Aloha
g.
Gary Kewley
CSO (Chief Surfing Officer)
1541 South Beretania St. Ste 207
Honolulu, HI. 96826
808-295-7873 (surf)