Guide to walk
across Mont-Saint-Michel bay

Source:
« Le Mont-Saint-Michel au péril de l’homme »
« Le Siècle volage » collection

pavillonf
Language

Mont-Saint-Michel land character establishment


It’s incongruous to discuss the re-establishment of Mont-Saint-Michel’s maritime character when a submersible ford to reach the rock is only submersed less than 40 hours per year. In 2015, works on new access infrastructures to the monument have been completed. Next sentence cannot be understood if it is not construed as a typical French understatement: "Mont-Saint-Michel is re-established in its maritime character."
The French President has ceremoniously told on 31th of October 2015, at the official opening of "re-establishment": "Today, Mont-Saint-Michel has been returned to the sea and for two years, the Mount is again circled by the flood tide during about forty hours a year; it was not like that any more since 1879."
Instead of forty hours, under normal conditions of pressure at sea level, the total duration of the high-seas slats during which, each year, Mont-Saint-Michel is "surrounded by the tide", is less. The table below is the product of calculations based on data provided by the Naval Hydrographic and Oceanographic Office (SHOM) and the Bureau des longitudes. To observe the Mont-Saint-Michel "surrounded by the tide", it has to be visible during daylight (4,898 yearly hours between the beginning of civil dawn and the end of civil twilight). These moments, rarer than a credulous President thinks, will they be able to pay the capital and running costs of the re-establishment works of maritime character? That is the question. You will find here in French an excerpt from La Revue Maritime, discussing this question in 2010, before launching the works told as re-establishment of Mont-Saint-Michel’s maritime character.

oOo

Annual duration of encirclement of Mont-Saint-Michel by the sea

…total

…daylight

…twilight

…at night

2022

0,3 ‰ - 02:59

0,0 ‰ - 00:14

0,1 ‰ - 00:51

0,2 ‰ - 01:54

2021

1,4 ‰ - 12:00

0,9 ‰ - 07:30

0,1 ‰ - 00:55

0,4 ‰ - 03:35

2020

3,5 ‰ - 30:20

1,5 ‰ - 13:10

0,4 ‰ - 03:09

1,6 ‰ - 14:01

2019

3,9 ‰ - 34:05

1,8 ‰ - 15:21

0,6 ‰ - 05:35

1,5 ‰ - 13:09

2018

1,2 ‰ - 10:42

0,5 ‰ - 04:31

0,3 ‰ - 02:27

0,4 ‰ - 03:44

2017

0,6 ‰ - 5:25

0,3 ‰ - 02:49

0,1 ‰ - 01:06

0,2 ‰ - 01:30

2016

3,4 ‰ - 29:42

1,7 ‰ - 15:17

0,3 ‰ - 02:32

1,4 ‰ - 11:53

Moyenne

2,0 ‰ - 17:53

1,0 ‰ - 08:24

0,3 ‰ - 02:22

0,8 ‰ - 07:06

Updated on December 28st 2021.
All ‰ reported times are computed with a denominator of 365 x 24 = 8,760 hours, except for leap years (366 x 24 = 8,784 hours).


2022, 2021, 2020, 2019, 2018, 2017 and 2016 timetables of
Mont-Saint-Michel
being "surrounded by the flood tide"
(in Central European Time UTC+1 (winter)
and Central European Summer Time UTC+2)
2022 timetable

Date

Mount circled by the flood tide

Morning or

evening twilight

Sunrise or

sunset

Tidal

coefficient

Start

End

Time

 

 

 

 

 

 

 

04/03/2022

8:12

8:26

0:14

7:12

7:44

103

 

 

 

 

 

 

 

13/08/2022

21:03

21:32

0:14

21:44

21:09

103

14/08/2022

21:45

22:15

0:30

21:42

21:08

102

 

 

 

 

 

 

 

11/09/2022

20:33

21:23

0:50

21:01

20:29

105

12/09/2022

21:14

21:58

0:44

20:59

20:27

103

 

 

 

 

 

 

 

10/10/2022

20:20

20:38

0:18

20:00

19:28

101

Updated on December 28st 2021.
2021 timetable

Date

Mount circled by the flood tide

Morning or

evening twilight

Sunrise or

sunset

Tidal

coefficient

Start

End

Time

 

 

 

 

 

 

 

01/03/2021

8:18

8:51

0:33

7:18

7:49

106

02/03/2021

8:56

9:31

0:35

7:16

7:47

105

 

 

 

 

 

 

 

29/03/2021

8:17

8:47

0:30

7:20

7:51

107

29/03/2021

20:40

21:14

0:34

21:06

20:34

111

30/03/2021

8:44

9:46

1:02

7:18

7:49

112

30/03/2021

21:14

22:03

0:49

21:07

20:35

112

31/03/2021

9:26

10:25

0:59

7:15

7:47

111

31/03/2021

22:01

22:27

0:26

21:09

20:37

107

 

 

 

 

 

 

 

27/04/2021

7:55

8:13

0:18

6:20

6:54

107

27/04/2021

20:13

20:48

0:35

21:52

21:17

110

28/04/2021

8:25

9:17

0:52

6:18

6:53

111

28/04/2021

20:50

21:37

0:47

21:53

21:18

111

29/04/2021

9:12

9:54

0:42

6:16

6:51

108

29/04/2021

21:45

21:56

0:11

21:55

21:20

105

 

 

 

 

 

 

 

12/09/2021

21:40

21:51

0:11

20:58

20:26

100

 

 

 

 

 

 

 

07/10/2021

20:21

21:14

0:53

20:05

19:34

107

08/10/2021

8:51

9:26

0:35

7:46

8:17

108

08/10/2021

20:58

21:54

0:56

20:03

19:32

107

09/10/2021

9:35

9:56

0:21

7:47

8:19

105

09/10/2021

22:07

22:18

0:11

20:01

19:30

101

Updated on December 21st 2020.
2020 timetable

Date

Mount circled by the flood tide

Morning or

evening twilight

Sunrise or

sunset

Tidal

coefficient

Start

End

Time

 

 

 

 

 

 

 

11/02/2020

8:13

9:00

0:47

7:48

8:21

108

12/02/2020

8:55

9:45

0:50

7:47

8:19

107

 

 

 

 

 

 

 

10/03/2020

7:11

8:01

0:50

6:57

7:28

110

10/03/2020

19:39

20:30

0:51

19:35

19:04

114

11/03/2020

7:44

9:00

1:16

6:55

7:26

116

11/03/2020

20:15

21:20

1:05

19:37

19:05

117

12/03/2020

8:27

9:43

1:16

6:53

7:24

115

12/03/2020

21:02

21:51

0:49

19:38

19:07

111

13/03/2020

9:20

10:05

0:45

6:51

7:22

106

 

 

 

 

 

 

 

08/04/2020

7:49

8:43

0:54

6:56

7:28

112

08/04/2020

20:13

21:11

0:58

21:20

20:47

115

09/04/2020

8:24

9:38

1:14

6:54

7:26

117

09/04/2020

20:52

21:58

1:06

21:21

20:49

116

10/04/2020

9:09

10:18

1:09

6:52

7:24

114

10/04/2020

21:39

22:26

0:47

21:22

20:50

110

 

 

 

 

 

 

 

21/08/2020

21:34

22:14

0:40

21:42

21:09

104

 

 

 

 

 

 

 

18/09/2020

20:20

21:30

1:10

20:43

20:11

112

19/09/2020

8:52

9:48

0:56

7:17

7:48

113

19/09/2020

20:59

22:16

1:17

20:40

20:09

113

20/09/2020

9:41

10:34

0:53

7:18

7:50

111

20/09/2020

21:47

22:46

0:59

20:38

20:07

107

 

 

 

 

 

 

 

16/10/2020

19:22

20:10

0:48

19:45

19:13

108

17/10/2020

7:46

8:39

0:53

7:57

8:29

112

17/10/2020

19:54

21:11

1:17

19:43

19:12

115

18/10/2020

8:21

9:31

1:10

7:59

8:31

115

18/10/2020

20:37

21:55

1:18

19:42

19:10

114

19/10/2020

9:06

10:07

1:01

8:00

8:32

111

19/10/2020

21:28

22:22

0:54

19:40

19:08

107

 

 

 

 

 

 

 

15/11/2020

18:43

19:32

0:49

18:00

17:25

109

16/11/2020

7:05

7:56

0:51

7:41

8:16

109

16/11/2020

19:29

20:16

0:47

17:59

17:24

108

Updated December 3rd 2019.
2019 timetable

Date

Mount circled by the flood tide

Morning or

evening twilight

Sunrise or

sunset

Tidal

coefficient

Start

End

Time

 

 

 

 

 

 

 

22/01/2019

7:36

7:54

0:18

8:12

8:47

105

23/01/2019

8:09

9:00

0:51

8:11

8:46

108

24/01/2019

8:58

9:42

0:44

8:11

8:45

106

 

 

 

 

 

 

 

20/02/2019

7:12

8:00

0:48

7:33

8:05

110

20/02/2019

19:44

20:28

0:44

19:06

18:34

113

21/02/2019

7:49

9:02

1:13

7:31

8:03

115

21/02/2019

20:23

21:19

0:56

19:08

18:36

115

22/02/2019

8:33

9:44

1:11

7:29

8:01

113

22/02/2019

21:13

21:49

0:36

19:09

18:37

110

23/02/2019

9:27

10:04

0:37

7:28

8:00

104

 

 

 

 

 

 

 

21/03/2019

6:55

7:45

0:50

6:36

7:07

111

21/03/2019

19:21

20:14

0:53

19:51

19:19

114

22/03/2019

7:30

8:42

1:12

6:34

7:05

115

22/03/2019

20:00

21:01

1:01

19:52

19:21

115

23/03/2019

8:13

9:21

1:08

6:32

7:03

113

23/03/2019

20:47

21:27

0:40

19:54

19:22

109

24/03/2019

9:09

9:35

0:26

6:30

7:01

104

 

 

 

 

 

 

 

19/04/2019

20:14

20:28

0:14

21:36

21:02

107

20/04/2019

8:22

8:59

0:37

6:33

7:06

108

20/04/2019

20:47

21:17

0:30

21:38

21:04

107

21/04/2019

9:09

9:27

0:18

6:31

7:04

105

 

 

 

 

 

 

 

03/08/2019

21:37

22:16

0:39

22:18

21:41

104

 

 

 

 

 

 

 

31/08/2019

20:24

21:32

1:08

21:23

20:50

112

01/09/2019

8:59

9:52

0:53

6:49

7:22

113

01/09/2019

21:05

22:22

1:17

21:21

20:48

113

02/09/2019

9:43

10:32

0:49

6:51

7:23

111

02/09/2019

21:54

22:56

1:02

21:19

20:46

107

 

 

 

 

 

 

 

28/09/2019

19:27

20:15

0:48

20:23

19:52

108

29/09/2019

7:53

8:45

0:52

7:30

8:01

113

29/09/2019

20:00

21:19

1:19

20:21

19:50

115

30/09/2019

8:30

9:38

1:08

7:32

8:03

116

30/09/2019

20:42

22:04

1:22

20:19

19:47

115

01/10/2019

9:14

10:15

1:01

7:33

8:04

112

01/10/2019

21:31

22:32

1:01

20:17

19:45

107

 

 

 

 

 

 

 

27/10/2019

18:13

18:43

0:30

18:27

17:55

106

28/10/2019

6:34

7:16

0:42

7:12

7:45

109

28/10/2019

18:45

19:46

1:01

18:26

17:53

111

29/10/2019

7:10

8:06

0:56

7:14

7:47

111

29/10/2019

19:28

20:27

0:59

18:24

17:51

109

30/10/2019

7:56

8:36

0:40

7:15

7:48

106

30/10/2019

20:28

20:39

0:11

18:22

17:50

102

Updated December 3rd 2018.

2018 timetable

Date

Mount circled by the flood tide

Morning or

evening twilight

Sunrise or

sunset

Tidal

coefficient

Start

End

Time

 

 

 

 

 

 

 

04/01/18

8:09

8:53

0:44

8:21

8:58

107

 

 

 

 

 

 

 

02/02/2018

7:55

8:49

0:54

7:59

8:33

109

03/02/2018

8:41

9:27

0:46

7:58

8:31

106

 

 

 

 

 

 

 

03/03/2018

7:40

8:29

0:49

7:11

7:42

110

04/03/2018

8:21

9:07

0:46

7:09

7:40

108

 

 

 

 

 

 

 

12/08/2018

20:33

21:22

0:49

22:01

21:26

109

 

 

 

 

 

 

 

13/08/2018

21:19

22:06

0:47

21:59

21:24

109

 

 

 

 

 

 

 

10/09/2018

20:11

21:12

1:01

21:01

20:29

111

11/09/2018

8:45

9:29

0:44

7:06

7:37

111

 

20:51

21:57

1:06

20:59

20:27

110

 

 

 

 

 

 

 

12/09/2018

21:40

22:23

0:43

20:56

20:25

104

 

 

 

 

 

 

 

09/10/2018

19:55

20:41

0:46

19:59

19:28

107

 

 

 

 

 

 

 

10/10/2018

20:35

21:22

0:47

19:58

19:26

106

Updated December 18th 2017.

2017 timetable

Date

Mount circled by the flood tide

Morning or

evening twilight

Sunrise or

sunset

Tidal

coefficient

Start

End

Time

 

 

 

 

 

 

 

30/03/2017

9:14

10:03

0:49

7:17

7:48

109

 

 

 

 

 

 

 

27/04/2017

20:33

21:20

0:47

21:48

21:14

110

28/04/2017

8:55

9:42

0:47

5:43

6:31

110

 

21:15

22:01

0:46

21:50

21:15

109

 

 

 

 

 

 

 

05/11/17

19:30

20:14

0:44

18:42

17:38

107

06/11/17

7:48

8:33

0:45

7:27

8:01

106

 

 

 

 

 

 

 

05/12/17

7:31

8:18

0:47

8:06

8:42

107

Updated December 3rd 2016.

2016 timetable

Date

Mount circled by the flood tide

Morning or

evening twilight

Sunrise or

sunset

Tidal

coefficient

Start

End

Time

 

 

 

 

 

 

 

11/02/2016

8:42

9:12

0:30

7:48

8:21

108

 

 

 

 

 

 

 

10/03/2016

7:33

8:28

0:55

6:57

7:28

115

 

19:59

20:45

0:46

19:35

19:03

116

11/03/2016

8:11

9:16

1:05

6:55

7:26

116

 

20:41

21:25

0:44

19:36

19:05

114

12/03/2016

9:01

9:46

0:45

6:53

7:24

111

 

 

 

 

 

 

 

07/04/2016

20:03

20:26

0:23

21:18

20:45

114

08/04/2016

8:12

9:08

0:56

6:55

7:28

117

 

20:33

21:29

0:56

21:20

20:47

118

09/04/2016

8:52

9:55

1:03

6:53

7:26

117

 

21:17

22:09

0:52

21:21

20:48

115

10/04/2016

9:44

10:23

0:39

6:51

7:24

111

 

 

 

 

 

 

 

07/05/2016

20:20

20:53

0:33

22:06

21:30

113

08/05/2016

8:49

9:12

0:23

5:45

6:33

112

 

21:05

21:33

0:28

22:08

21:31

110

 

 

 

 

 

 

 

17/09/2016

20:17

20:47

0:30

20:45

20:13

108

18/09/2016

8:46

9:00

0:14

7:15

7:46

110

 

20:48

21:43

0:55

20:43

20:11

111

19/09/2016

9:18

9:53

0:35

7:16

7:48

111

 

21:33

22:19

0:46

20:40

20:09

108

 

 

 

 

 

 

 

16/10/2016

19:47

20:33

0:46

19:45

19:13

111

17/10/2016

8:08

8:57

0:49

7:57

8:29

114

 

20:24

21:27

1:03

19:43

19:11

114

18/10/2016

8:48

9:43

0:55

7:59

8:31

113

 

21:12

22:03

0:51

19:41

19:09

111

19/10/2016

9:42

10:06

0:24

8:00

8:32

106

 

 

 

 

 

 

 

15/11/2016

6:51

7:26

0:35

7:40

8:15

111

 

19:15

19:55

0:40

17:59

17:24

112

16/11/2016

7:32

8:17

0:45

7:41

8:16

111

 

20:08

20:28

0:20

17:58

17:23

109

Updated January 15th 2016.

Operating instructions

This timetable has been computed with:
- tidal predictions, issued by Service hydrographique et océanographique de la Marine (SHOM) for Saint-Malo, as Mont-Saint-Michel port of reference (computed two years in advance);
- threshold of the submersible ford, established at 12.90 m above Saint-Malo chart datum (Lowest Astronomical Tide) spot height.
Used SHOM predictions are computed with an accuracy of some centimeters for the heights and some minutes for the hours. They may differ slightly (see examples) from the in-line predictions, established on up to date data.

The Tourist office and the Town of Mont-Saint-Michel take 12.85 m as threshold value. At this level, due to predictions uncertainty, a risk of ford submersion exists. A risk is never sure. The 12.90 m level, computed by surveying engineers, is obviously the only one to take in order to be certain to move and see a real spectacle. For your information, at 12.90 m level, under normal sea level conditions of pressure, how long high tide slacks in 2019, Mont-Saint-Michel, being circled by the flood tide, will only last 34 hours and 05 minutes (3.9 ‰ of a year).

In blue, morning tides, in fuchsia, evening tides.

Night begins after sunset at the end of evening civil twilight and finishes at the beginning of morning civil twilight before sunrise.
Black schedules are night ones to avoid.
Silver grey schedules might lack of light to take pictures.

This schedules don't consider correction terms for barometric pressure. They are computed for a 1 013 hectopascals sealevel pressure.
Water level varies with atmospheric pressure from 1 cm by hectopascal:
- with a pressure greater than 1 013 hPa (anticyclonic periods), sea level is lower than the computed one; high tide slack times, when Mont-Saint-Michel is circled by the flood tide, are reduced and eventually, Mount cannot be circled when tidal coefficient is insufficient;
- with a pressure lower than 1 013 hPa (Low system), sea level is higher than the computed one; high tide slack times, when Mont-Saint-Michel is circled by the flood tide, are so longer.

Wind conditions can also change the computed water level:
- by North to South-West winds, tide is flushed offshore; high tide sea level is then lower than computed;
- by West to North-West winds, tide is pushed inshore; high tide sea level is then higher than computed.

Mont-Saint-Michel pictures (© Century Flyer) above have been taken on the 29th of October 2015 at 07 h 56 and 08 h 04 respectively, once the monument circled by the flood tide. Tidal coefficient was 112. High tide was computed for 07 h 54. As may be seen, while mid-term school holidays were in full swing, there was hardly anyone there to enjoy this staggeringly expensive spectacle!

PS. Computations made with SHOM tidal predictions for Saint-Malo have not been revised by SHOM. They are established under the sole responsibility of the editor.