ʻAle / Swells

Produced by winds, swells are waves that travel beyond the area where they were formed. On the Hawaiian star compass, swells move in a straight line from one point on the horizon to another point 180° away, on the opposite side of the circle of the horizon. Swells can persist from the same direction for several days or longer and thus, can be used to orient a vessel at sea. Swells reflecting off of or refracting around an unseen island are clues to its presence & bearing. Waves are generated by local winds and change directions with shifting local winds. (Waves also refer to swells that approach coastlines and become breakers.) Seas refer to the state of the ocean surface, with swells and waves interacting.

Kai / Tides

Tides are caused by grativational pull of the moon, and to a lesser extent, the sun. Tidal currents are caused by the rising and falling of the tide; the highest tides occur when the sun and moon are aligned (new moon and full moon). Near-shore tidal currents tend to flow parallel to shorelines. They may counteract or enhance surface currents and may change directions when the tide changes. When the tidal current is flowing against the swells, they reduce the wave speed and and increase wave steepness; when the tidal current is running with the seas, the steepness of the wave decreases.

kai piʻi: rising tide kai nui: high tide kai piha: full tide; spring tide kai kū: standing tide, between the ebb and flow kai moku: tide begins to fall or ebb kai emi: falling tide kai make: low tide kai maloʻo: dry sea, when the reefs are exposed at low tide au miki: outgoing current au kā: incoming current Ke-aumiki and Ke-aukā were gods of the tides and winds

Au / Currents

Surface Currents are produced by wind blowing on the ocean surface and by temperature and pressure variations in the ocean; surface currents around Hawaiʻi generally flow westward at .3 – .5 knots. Eddies form south of the islands due to the mixing of warm lee waters and upwellings of cool water along wind shear lines between the lee calms and trade wind flow.

au: current au wili: swirling, twisting current, caused when two currents meet such as at Kalae (South Point) on the Big Island where Halaʻea, the current from the east side of the island, meets Kāwili (lit. “hit and turn”), the current from the west side. kai kō: sea with a strong current au kanaiʻi: strong current; said of a strong warrior au nui: big current au iki: little current

Because the knowledge of currents is so important to fishing and voyaging, and currents are difficult to detect at sea, they have become metaphors for extensive knowledge, as in the following proverbs from Mary Kawena Pukui’s ʻŌlelo Noʻeau:

ʻIke i ke au nui me ke au iki. “Knows the big currents and the little currents.”

Interpretation: The person is very well versed in something. (No. 1209)

E kuhikuhi pono i nā au iki a me nā au nui o ka ʻike: “Instruct well in both the little and the great currents of knowledge.” Interpretation: In teaching, the small details are as important as the large ones. (No. 325)

ʻAʻohe o kāhi nānā o luna o ka pali; iho mai a lalo nei; ʻike i ke au nui ke au iki, he alo a he alo: “The top of the cliff isn’t the place to look at us; come down here and learn of the big and little currents, face to face.” Interpretation: Learn the details. Also, an invitation to discuss something. Said by Pele to Pāʻoa when he came to seek the lava-encased remains of his friend Lohiʻau. (No. 197)

Rip Current

A rip current is caused by the seaward flow of water pushed to shore by incoming waves. When a rip currents seems to be pulling the swimmer from underwater, its is called an undertow.

au kō malalo: undertow

See figure 88, from Oceanography and Seamanship, 2nd Edition, by William G. Van Dorn (Centreville, Maryland: Cornell Maritime Press, 1993).