Tides & Currents

Question 1

In the north east of the US, we experience 2 high and 2 low tides each day. What do we call this type of tide cycle?

A. Spring

B. Mixed

C. Semi-diurnal

D. Diurnal

Answer 1

C. Semi-diurnal

Question 2

What type of tide produces higher than average high tides and lower than average low tides?

A. Extreme

B. Nodal

C. Neap

D. Spring

Answer 2

D. Spring

Question 3

What type of tide is experienced when the moon is in the first quarter or last quarter?

A. Spring

B. Neap

C. Mixed

D. Diurnal

Answer 3

B. Neap

Question 4

The point where the vertical rise of the tide has reached its peak is called the __________ of the tide.

A. Epoch

B. Top

C. Stand

D. Spring

Answer 4

C. Stand

Question 5

The point where tidal current flow has reached its minimum velocity is called _____________ water?

A. Stand

B. Slack

C. Low

D. Still

Answer 5

B. Slack

Question 6

A Diurnal tide cycle will have how many high tides in a 24 hour period?

A. 0

B. 1

C. 2

D. 4

Answer 6

B. 1

Question 7

It takes the moon approximately __________ days to orbit the earth?

A. 21

B. 28

C. 30

D. 31

Answer 7

B. 28

Question 8

Depth soundings on most NOAA charts will be given in reference to ____________?

A. Mean low water

B. Mean high water

C. Mid lower low water

D. Mean lower low water

Answer 8

D. Mean lower low water

Question 9

On a NOAA chart, vertical clearances and height of shore side structures such as lighthouses is given in reference to _____________?

A. Mean high water

B. Mean lower low water

C. Chart datum

D. Mean higher high water

Answer 9

A. Mean high water

Question 10

The time and heights of high and low tides may be found in what reference volume?

A. Light List

B. Chart One

C. Tide Tables

D. Tidal Current Tables

Answer 10

C. Tide Tables

Question 11

When the tide is rising and we are approaching high water, this is called a _____________ tide?

A. Incoming

B. Ebb

C. Flood

D. Washing

Answer 11

C. Flood

Question 12

The difference in height between consecutive high and low tides is called _____________?

A. Tidal duration

B. Tidal epoch

C. Tidal flow

D. Tidal range

Answer 12

D. Tidal range

Question 13

Due to wind and changes in atmospheric pressure, this tide is called a ___________________?

A. Astronomical tide

B. Max tide

C. Meteorological tide

D. Spring tide

Answer 13

C. Meteorological tide

Question 14

Tides are the periodic rise and fall of a body of water due to gravitational pulls between the __________________?

A. Sun, Jupiter and Earth

B. North star, moon and sun

C. Stars, Earth and sun

D. Sun, moon and Earth

Answer 14

D. Sun, moon and Earth

Question 15

The Tidal Day is ___________ hours?

A. 23.84

B. 24.84

C. 24.48

D. 23.48

Answer 15

B. 24.84

Question 16

The moon’s gravitational force is greater than the sun and therefore has a greater effect on tides.

A. True

B. False

Answer 16

A. True

Question 17

Spring tides have a larger tidal range than Neap tides?

A. True

B. False

Answer 17

A. True

Question 18

The __________________ causes wind currents to deflect to the right in the Northern Hemisphere?

A. Tropic Effect

B. Sub-Tropical Effect

C. Banking Effect

D. Coriolis Effect

Answer 18

D. Coriolis Effect

Question 19

In the open ocean tidal currents are said to be ________________ because the current spins _________________ in a tidal period?

A. Counter- rotary, 360 degrees counterclockwise

B. Rotary, 360 degrees clockwise

C. Rotary, 360 degrees counterclockwise

D. Sub-rotary, 360 degrees clockwise

Answer 19

C. Rotary, 360 degrees counterclockwise

Question 20

The prudent mariner must always factor in tides and currents when approaching harbors, inlets and navigable waters in both inland and international waters?

A. True

B. False

Answer 20

A. True