Chinese Proverb"the third day of water, the eighteen of tide"in the Folk World, it is only suitable of which is mainly semidiurnal tide sea, and it is not suitable of which is mainly diurnaltide sea.
民间“初三水，十八潮”的谚语，只适用于半日潮为主的海域，对于全日潮为主的海域不适用。
2
The semi-diurnal and diurnal internal tide energy densities are large on the continental shelf and in the thermocline of the deep sea.
This procedure applies only to regular semidiurnal tidal waters forecasts and cannot accurately predict full-tide waters (such as the North Bay) and irregular diurnal tidal waters.