High Island Surf Cam, Ocean Rip Currents, Ocean Safety Sign

There are three basic swell sources that can reach Hawaii's shores from all directions: the east-northeast trade winds, the North Pacific lows, and the South Pacific (Southern Hemisphere) lows. Hurricanes and Kona winds from the local southwest can also create high surf during the winter, although surf from these two sources are not common in Hawaii.

Easterly swell

The trade winds bring in relatively low swells two to six feet high from an Easterly direction throughout most of the year. On occasion, the trade wind belt is pointed toward Hawaii for long periods of time during which winds 25-30 knots and 8 to12 foot swells can reach the islands. Hurricanes can also send large waves into the Islands from the east as well.

Southerly swell

The highest southerly surf in Hawaii is usually due to large storms near New Zealand. Southern Hemisphere storms or gales generate southerly swells pointed toward the islands during the Northern Hemisphere's summer. Although not exceptionally high (surf over 10 feet is rare), they do cause problems at entrances to south-facing harbors and anchorages. These south swells can cause damage to shoreline property and boats and can last several days before diminishing in size. These swells have the longest period (time interval between two wave crests is longer than 16 seconds) of all the swells to reach the Hawaii islands because of the great distance traveled.

Northerly swell

When a gale or storm develops during the winter within 1,500 miles northeast of the Hawaiian islands, folks can expect a northerly swell to roll in. Although surf heights rarely exceed 20 feet, the surges caused by the high swells and accompanying northerly winds can disrupt operations in Hilo, Hawaii, and Kahului, Maui harbors.

Northwesterly swell

Spectacular high surf can be found along Hawaii's northern and western shores during the winter due North Pacific gales and storm low fronts. Such storms are very large with very strong northwest winds. The northern and western shores of all Hawaiian islands are affected by these waves, but some areas of Molokai, Lanai, Maui, and Hawaii are partly sheltered by other islands.

High Surf