The Dover Straits - English
60 nautical (sea) miles = 1°of latitude
1 nautical (sea) mile = 1minute of latitude
1 nautical (sea) mile is 2000 yards - 1852
metres - 1.852 Kilometres.
0.1 of a nautical (sea) mile is 200 yards --
English Channel chart - Part of practice chart
5505. Reproduced by permission of the Admiralty charts & publications. This
chart is not to scale and must not be used for
Q. How far do
you travel to get from England to France?
A. The English Channel is
19 nautical miles (38000 yards)
35 kilometres (35000 mtrs) - wide.
Its narrowest point is Shakespeare Beach, Dover to
Cap Gris Nez, France which is 18.2 nm.
are a little longer so you can expect to swim about 20 nm - 37 km.
The Tides are strong and change
direction ,approximately every 6 hours.
They flow to the North
East from about 1.5 hours before high water to about 4.5 hours after high water
Then turn and flow South West from
4.5 hours after high water to 1.5 hours before high water (Ebb tide).
tides can flow at up to 4 nautical miles per hour.
The tide gets later
every day by about 30 to 50 mins and change in height and flow speed every
The lowest flow/ height range is known as
the NEAP TIDES
The highest flow/height range is the SPRING
See the channel
Q. How does the tide affect the
A.Think of the English Channel as a river
between two lumps of land.
Every 6.2 hours- approximate- the tide changes
its direction by 180 degrees and flows back to where it came
From about 1.5 hours before High Water to
about 4.5 hours after high water the tide flows towards the North East (from
bottom left hand corner of chart to top right hand corner). This is known as
the FLOOD TIDE
It then turns through 180 degrees
and flows back from where it came. That's towards the South west. The South
West flow is from about 4.5 hours after high water to 1.5 hours before High
Water. This is known as the EBB TIDE.
matters more the gravitational pull on the water mass from the sun and the moon
vary depending on the position of the moon.
a 14 day cycle and it produces what we call SPRING & NEAP
To be brief --- SPRING tides are when the
moon and the sun are in line with each other.
is at the NEW & FULL moons.
At these times the
tidal movement is at its greatest. (The largest amount of water moving up and
then down the Channel is when there is a new moon)
NEAP tides are when the sun and the moon are at right angles to
each other. This is when there is a HALF moon.
this time the tidal movement is at its lowest (the smallest amount of water
moving up and down channel.
At Dover --- The top
of the SPRING tides are when the tide table readings are about 6.8 metres or
above for High Water and 0.8 metres or below for Low water.
That means that the water will rise and fall by 6 metres plus between
Low - High - Low water approximately every 12.4 hours.
The bottom of the
NEAP tides are when the tide table readings are about 5.3 metres or below for
high water and 2 metres or below for LOW water. That means that the water will
rise and fall by 3.3 metres or less between low - High - Low water every 12.4
As you can see there is nearly twice as
much water moving on the top of the SPRING tide as there is at the bottom of
the NEAP tide.
This change is gradual over the 7
days between SPRINGS & NEAPS The full cycle is every 28 days. (Neap - high
spring - neap - low spring - neap)
This is a Lunar
For Channel swimming purposes we consider
NEAP TIDES to be anything BELOW 6.1
SPRING TIDES to be anything above 6.1
How does this affect the crossing?
- on a 5.3 metre NEAP tide the water will carry a row about 7 to 7.5 nm up
Channel on the Flood tide and then come back 7.5 to 8 miles on the Ebb
On a 6.8 metre SPRING tide the swimmer will be carried about 13 nm up
Channel on the Flood tide and then come back 15 nm on the EBB tide.
You do not actually row
these distances as you are rowing across the tide but your course will be in
a long curve, or curves, depending on the rate you row at. The distance you
travel up and down Channel is about the same and cancels each other out
although the exact effect it has on your crossing will depend on the skill of your
pilot. An average row across the Channel between Dover and France is between 4 and 6 hours.
Q. When is the best time to cross -
A.The best time to make an attempt is when the weather is stable
and the sky is overcast giving a sea and land temperature that is about the
same and when there is little or no wind.
is usually in mid December -- the rest of the year is compromise and suspect.
The weather in the Dover Straits is a very fickle thing.
The Weather is the most important factor in any crossing but it is
hard to predict and many a team has sat on the beach on a flat calm day
because the forecast did not match what happened.
There are also the days when the forecast has been good and the
The weather is often
better on the SPRING tides but the piloting requires a lot more skill. The
pilot and team have to work together to get the course right as the pilot
has to estimate the speed more accurately and know the tide runs to be in
the right place at the right time.
It is all
very "Swings & Roundabouts" as we say. I think the mental attitude of the
team members is very important as well. The right frame of mind is -- " have a go
and be confident, do not worry about failure, just think success."
many years at sea delivering boats all over Europe and teaching people to
handle boats I have a little saying that I often have to quote to myself in
times of need - it also applies to open water rowing: Before you make a
decision -- assess your abilities -- respect your limitations -- never lie to
yourself -- be positive and go for your "goal"
"Experiance is often something you gain just after you need it".
"Nothing great is easy, know your limitations before you exceed them."