A low water whose predicted height is negative, meaning it drops below MLLW or whatever datum the table uses. On the US Pacific coast and in Alaska, minus tides around springs expose rarely seen intertidal zones and bring out clam diggers, tidepoolers and field biologists. The deepest ones, minus two feet or lower, cluster around the solstices in many West Coast locations.
Minus tide of minus 1.8 at 0640 Saturday, best clamming of the month if you're up early.
Also heard as
- negative tide
- minus low
Related terms
MLLW
Mean Lower Low Water: the average height of the lower of each day's two low waters, used as chart datum in the United States.
Low-low
Shorthand for the lower low water of the day in places with mixed tides.
Chart datum
The low-water zero that charted depths and tide table heights are measured from.
Dead low
The very bottom of low water, when the tide has stopped falling and not yet started to rise.