NORTH SHORE (KHNL) -- They may not have been big enough for the Eddie Aikau, but they were still monster waves.
Hawaii's only news helicopter caught video of the large swells, with 20 to 30 foot sets and brave surfers looking for that perfect ride. A high surf warning will remain up through Friday morning.
The dangerous waves attracted some dare-devils to Oahu's North Shore Thursday, despite a high surf warning.
The waves were so strong, some surfers ended up on the injured list. The giant waves crashed so hard along the North Shore, police blocked off some beach access points.
Dangerous swells attracted surfers to Waimea Bay, eager for an adrenaline rush. But some of those attempting to catch that natural high, left with much more.
"One of them suffered a laceration to his chin, a pretty deep laceration to his chin. And the other one was held down under a few waves and actually inhaled some water," said Kerry Atwood, a lifeguard.
The giant waves also broke boards, hurting some surfers' pocket books.
"It was sort of a hand-me-down from a friend but brand new, these things are quite expensive. $900 or something so yeah, I'll have to find a replacement somehow," said Dustin Jones, a surfer from Haleiwa.
Lifeguards reported the surf in the 15 to 18 foot range. But those in the water say the waves they confronted were much higher.
"I would say some of them are getting even bigger than that, sort of 35ish on the face," said Andrew Marr, a surfer from South Africa.
Lifeguards warn that waves this powerful should be reserved for experienced surfers, not amateurs.
"Know your limit and if you are not conditioned and if you're not experienced with this kind of surf we strongly recommend that you just be a spectator," said Atwood.
But the beauty of the Mother's Nature's sheer force still attracted up to 75 surfers, with hundreds of people coming out on Valentine's Day to watch them. The high surf warning will remain up until 6:00 a.m Friday.
The warning is posted for north and west facing shores of most islands. Waves as high as 20 to 30 feet are expected through Friday.