When boating on coastal waters, it is important to be aware of the tides. why?

Predicting tides has always been important to people who look to the sea for their livelihood. Commercial and recreational fishermen use their knowledge of the tides and tidal currents to help them improve their catches. Depending on the species and water depth in a particular area, fish may concentrate during ebb or flood tidal currents. In some areas, strong tidal currents concentrate bait and smaller fish, attracting larger fish. In addition, knowledge of the tides has also been of interest to recreational beachgoers and surfers.

On June 14, 2002, these four industrial cranes, valued at approximately $1.25 million each, arrived in San Francisco Bay from Shanghai, China. Designed to rapidly hoist 40-foot-long containers from super-sized cargo ships, they had to be transported beneath the Oakland Bridge to reach their final destination, the Port of Oakland. The tidal range of San Francisco Bay when these cranes were transported was 4.1 feet and the bridge had a motion of approximately 6 inches. With light chop on the bay and winds blowing at around 10 mph, there was little room for error. With detailed knowledge of the tidal cycle and skillful piloting of the vessel, the cranes cleared the bottom of the bridge by about 6 feet.

Navigating ships through shallow water ports, intracoastal waterways and estuaries requires knowledge of the time and height of the tides as well as the speed and direction of the tidal currents. This was particularly critical to sailing ships because they had to take advantage of the tides and currents to maneuver correctly. Knowledge of tides and currents is still critical because today’s vessels are much larger than the old sailing ships. The depths and widths of the channels in which they sail, and the increased marine traffic leaves very little room for error. Real-time water level, water current, and weather measurement systems now are being used in many major ports to provide mariners and port operators with the latest conditions.

Coastal zone engineering projects, including the construction of bridges, docks, etc., require engineers to monitor fluctuating tide levels. Projects involving the construction, demolition or movement of large structures must be scheduled far in advance if an area experiences wide fluctuations in water levels during its tidal cycle. Habitat restoration projects also require accurate knowledge of tide and current conditions.

Scientists are concerned with tides, water levels and tidal currents as well. Ecologists may focus on the tidal mixing of near-shore waters, where pollutants are removed and nutrients are recirculated. Tidal currents also move floating animals and plants to and from breeding areas in estuaries to deeper waters. Oceanographers or atmospheric scientists may study tidal fluctuations to better understand the circulation of the ocean and its relationship to world climatic changes.

Marine commerce is an area in which tide and current predictions are critical. In June 2002, these four marine cranes valued at $5 million cleared the Oakland Bridge in San Francisco Bay by approximately 6 feet. If you look carefully in the center of the image, you can see a shadowed figure between the crane and the bridge. This is one of the mariners standing on top of the crane and touching the bottom of the bridge as the barge passes beneath it.

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Understanding tides

Originating in the ocean tides are long-period waves that move through the ocean towards the coastlines where they appear as the regular rise (flood) and fall (ebb) of the sea surface. The extent of the rise and fall and the frequency with which it occurs varies from place to place over a 12- hour cycle. Tides are influenced by the gravitational pull of the Moon, Sun and the Planets. When the sun, moon are in line with the earth earth you can expect the highest and lowest tides.known as Spring Tides) When there is a half moon you can expect very high or low tides.(known as Neap Tides) A "King Tide" refers to an exceptionally high tide which typically occur during a new or full moon period.

Spring tides

Spring tides occur at the time of a full moon. During this period the high tide will be higher and the low tide lower than average. A King Tide, is a colloquial term for an especially high spring tide. The use of the term "king tide" originated in Australia, New Zealand and other Pacific nations to refer to an especially high tide that occurs only a few times per year. The term is now used in North America as well, particularly in low-lying South Florida, where they cause sunny day tidal flooding. King tides occur because of the combined influence of a number of astronomical factors related to the Sun and the Moon, and their alignments relative to Earth.

When king tides occur during cyclones, floods or storms, water levels can rise to higher levels and have the potential to cause great damage to property and the coastline. During normal weather conditions the height of the king tides will be similar from year to year.

Neap tide

A Neap tide will occur after the first and last quarter of the lunar month. During this period the high tide is lower than usual and the low tides are higher than usual.

Tidal currents

Horizontal movement of water often accompanies the rising and falling of the tide. This is called the tidal current. The incoming tide along the coast and into the bays and estuaries is called a flood current; the outgoing tide is called an ebb current. The strongest flood and ebb currents usually occur before or near the time of the high and low tides. The weakest currents occur between the flood and ebb currents and are called slack tides. In the open ocean tidal currents are relatively weak. Near estuary entrances, narrow straits and inlets, the speed of tidal currents can reach up to several kilometers per hour.Most coastal areas experience two high tides over a 24 hour period. High tides occur 12 hours and 25 minutes apart, taking approximately six hours for the water at the shore to go from high to low, or from low to high.

Tidal effects

The shape of bays, estuaries as well as local wind and weather conditions can combine to magnify the intensity of tides. Strong offshore winds can move water away from coastlines, exaggerating low tide exposures. Onshore winds may act to pile up water onto the shoreline, virtually eliminating low tide exposures. High pressure systems can depress sea levels, leading to clear sunny days with exceptionally low tides. Conversely, low pressure systems that contribute to cloudy, rainy conditions typically are associated with tides than are much higher than predicted.

Tide Predictions

The Australian Bureau of Meteorology's (BOM) Tidal Portal shows tide times and heights for approximately 700 locations around Australia.

Boat operators in coastal waters need to be mindful of the effect of tides. The rise and fall of tides can cause water levels to fluctuate by several feet and also can generate strong currents. Some tidal currents are strong enough that some boats cannot make headway against the current.

Why is it important to know the tides?

We study tides for safe navigation recreation and coastal development. … Tidal data is also critical to fishing recreational boating and surfing. Commercial and recreational fishermen use their knowledge of the tides and tidal currents to help them improve their catches.

What can tides cause PWC?

Tides cause electrical storms and hurricanes.

What is are the importance S of predicting the height of the tide of a certain international port?

Predicting and measuring tides and currents is important for things like getting cargo ships safely into and out of ports determining the extent of an oil spill building bridges and piers determining the best fishing spots emergency preparedness tsunami tracking marsh restoration and much more.

What are the 3 things tides are caused by?

The tides–the daily rise and fall of the sea’s edge–are caused by the gravitational forces between the earth the moon and the sun. Since the moon is closer to our planet than the sun it exerts a stronger gravitational pull on us. (The sun only has 46% of the tide-generating force of the moon.)

Why is ocean tides important?

Tides affect other aspects of oceanic life including the reproductive activities of fish and ocean plants. Floating plants and animals ride the tidal currents between the breeding areas and deeper waters. The tides help remove pollutants and circulate nutrients ocean plants and animals need to survive.

How are tides monitored?

In the past tides were measured and monitored using mechanical systems and recording devices which would often float in the water. However present day tide monitors utilize electronics and acoustics on an electric system to monitor the tides.

How do tides affect boating?

Rising and falling tides can wreak havoc on any type of boat tied tight to a dock. … Water depth that may offer enough scope at low tide may not offer enough angle for your anchor to keep you boat put at high tide on the other hand anchoring in shallow water at high tide may strand your boat when the tide drops.

How do tides impact coastal areas?

The role of tides in molding coastal landforms is twofold: (1) tidal currents transport large quantities of sediment and may erode bedrock and (2) the rise and fall of the tide distributes wave energy across a shore zone by changing the depth of water and the position of the shoreline. …

Is it better to boat during high tide or low tide?

The best time to dock is during a slack tide. The minimal water movement is ideal for boaters as long as the winds are not too strong. A low tide may moor your boat before you have a chance to reach the correct docking area. A high tide also will prevent you from reaching the place where you need to dock.

What is the importance of tides Class 7?

Importance of Tides

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High tides help in navigation. They raise the water level close to the shores. This helps the ships to arrive at harbour more easily.

What is the importance of Admiralty tide tables?

It is accompanied by tables to assist in the prediction and analysis of the tides. Its purpose is to set forth an entirely new method for the prediction of tides and tidal currents which has now been adopted ‘as the standard method of the British Admiralty be ginning with the year 1937.

What are the reasons why oceanographers able to predict the tide with great accuracy?

As these bulges move around Earth they run into land causing the water level to rise and fall. So the most important factors in predicting the tides are the positions of the Sun and Moon — their distance from Earth their direction in space and how they’re moving.

What do you understand by ocean tides explain how ocean tides are formed and its effect?

The Short Answer:

High and low tides are caused by the moon. The moon’s gravitational pull generates something called the tidal force. The tidal force causes Earth—and its water—to bulge out on the side closest to the moon and the side farthest from the moon. These bulges of water are high tides.

What do you understand by ocean tides?

Tides are very long-period waves that move through the oceans in response to the forces exerted by the moon and sun. Tides originate in the oceans and progress toward the coastlines where they appear as the regular rise and fall of the sea surface.

What are tides quizlet?

What are tides? Tides are daily changes in the elevation of the ocean surface. Ocean tides result from the gravitational attraction exerted upon earth by the moon and to a lesser extent by the sun.

How do tides help us?

The Importance of Tides:

They raise the water level close to the shores. This helps the ships to arrive at harbour more easily. 2. The high tides also help in fishing.

How are tides useful for fishermen?

Tides move water bringing water in and taking water out. … The full and new moons normally create better fishing conditions because of the spring tides. The reason behind this is that fish are easier to catch when they are feeding and it’s the tide and currents that dictate this.

How do river tides work?

A tidal river is a river whose flow and level are influenced by tides. … In some cases high tides impound downstream flowing freshwater reversing the flow and increasing the water level of the lower section of river forming large estuaries. High tides can be noticed as far as 100 kilometres (62 mi) upstream.

How are tides caused?

The moon’s gravity pulls the ocean toward it during high high tides. During low high tides the Earth itself is pulled slightly toward the moon creating high tides on the opposite side of the planet. Earth’s rotation and the gravitational pull of the sun and moon create tides on our planet.

What are tides measured against?

Keep in mind that all tidal heights are measured against the defined plane of reference called Chart Datum. Chart Datum is basically an average of low tide heights. Nautical charts use this same reference to measure depth.

What other types of information is collected at tide monitoring stations?

These include wind speed and direction water current speed and direction air and water temperature and barometric pressure. Like the old recorders the new measuring stations collect data every six minutes.

How do you tide a boat?

Do tides affect wind?

Tides influence sea breezes in two ways. … Depending on the direction of the tidal flow with respect to wind direction the wind speed over the open North Sea is increased (or decreased) by around 0.2 m/s. Furthermore an influence of tides on the atmosphere is found not only directly at the coast.

How does the tide in a river helps a vessel and what is the hindrance navigating on a river?

In astronomical-geographic terms a tide signifies the gravitational pull of the moon. … In water-parts like these the presence of a low tide will moor the vessel even before it can dock at the dockyard and a high tide will disallow a vessel to dock at the required area.

Why are waves and tides important?

Waves transmit energy not water and are commonly caused by the wind as it blows across the ocean lakes and rivers. Waves caused by the gravitational pull of the moon and the sun are called tides. The ebb and flow of waves and tides are the life force of our world ocean.

What are the importance of coastal landforms?

The greater the tidal range the more effect this phenomenon has on the coast. The slope of a beach or other coastal landform also is important however because a steep cliff provides only a nominal change in the area over which waves and currents can do their work even in a macro-tidal environment.

How do tides cause coastal erosion?

Coastal erosion involves moving the shoreline (where land and water meet) further towards land. It also involves a decrease in the size of the beach as sediments are taken away by the sea. … The sand is then slowly pushed back onto the beach by waves and tides over a period of weeks months or even years.

What are boat trailer ratings based on?

Federal law requires that a trailer display its GVWR (Gross Vehicle Weight Rating) which is the total weight the trailer is rated to carry including the boat engine gasoline (six pounds per gallon) water (eight pounds per gallon) and gear.

What type of tide occurs when the sea level is at its lowest?

Low – Low tide is the point in the tidal cycle where the sea level is at its lowest. Spring – Spring tide occurs when the Sun and the Moon are aligned to combine for the largest tidal range of the highest high tide and the lowest low tide.

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What is the difference between low tide and high tide?

As the tide rises water moves toward the shore. … When the highest part or crest of the wave reaches a particular location high tide occurs low tide corresponds to the lowest part of the wave or its trough. The difference in height between the high tide and the low tide is called the tidal range.

What is the importance of tides Class 11?

Importance of Tides

Tidal heights are very important especially harbors near rivers and within estuaries having shallow ‘bars’ at the entrance which prevent ships and boats from entering into the harbour. Tides are also helpful in desilting the sediments and in removing polluted water from river estuaries.

What are tides for Class 7?

Answer: The rhythmic rise and fall of ocean water twice in a day is called a tide. Tides are caused by the gravitational force exerted by the sun and the moon on the earth’s surface.

What is the important to know the tide level at particular location?

Predicting tides has always been important to people who look to the sea for their livelihood. … Depending on the species and water depth in a particular area fish may concentrate during ebb or flood tidal currents. In some areas strong tidal currents concentrate bait and smaller fish attracting larger fish.

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