Groix tides today
- Tide now 12.0 ft ↑ rising · high 6:02 am (16.2 ft)
- Best time to fish 11:50 am–12:50 pm good day · 7/10
- Beach day Not today Not a beach day · 0/10
- Waves · water 6.1 ft · 55 °F moderate · 10.9 s from the west
- Wind · air 12 mph · 52 °F from the ENE, gusts 16 · overcast
- Surf today 3.1–4.8 ft Good day · 7/10 · 12:00–4:00 pm
- Sun 7:53 am–6:01 pm 10 h 8 min of daylight
- Moon 85% · 8:02 pm waning gibbous · rises at 8:02 pm
Today in Groix there are high tides at 6:02 am (16.2 ft) and 6:31 pm (15.6 ft) and low tides at 12:06 am and 12:35 pm. Tide coefficient 93. Right now the tide is rising toward the high tide at 6:02 am. The sun rises at 7:53 am and sets at 6:01 pm: 10 h 8 min of daylight. The moon is 85% illuminated (waning gibbous) and rises at 8:02 pm. Major solunar periods run from 2:40 am to 4:40 am and from 3:12 pm to 5:12 pm. The next spring tides arrive from November 9 to 11. The sea is moderate, with 6.1 ft waves. There's a moderate breeze from the east-northeast (12 mph). Overcast, 52 °F.
Fishing in Groix today
Best time to fish
Solunar activity today: medium- Low tide at 12:35 pm
- Minor period 11:52 am–12:52 pm (moonset)
- Falling pressure (−0.09 inHg in 24 h), moderate offshore wind (13 mph) and 4.9 ft waves
- Waning gibbous: a bit more activity than at the quarters
- Highest tide coefficient today: 93 (spring tides)
Your day at a glance
The best window, 11:50 am to 12:50 pm, combines the 12:35 pm low tide, moonset and falling pressure, though with moderate wind. Also worth a try from 4:30 pm to 7:30 pm, with the 6:31 pm high tide, a major period, sunset, falling pressure and some swell, though with moderate wind.
Species with the most records nearby: European hake, common sole, European conger and Atlantic horse mackerel. October is one of the months when these are seen most: European conger and common cuttlefish. What you can catch
Beach day in Groix
Is it a beach day?
- Low tide at 12:35 pm: more sand
- Cloudy (99% cloud cover)
- Feels like 53 °F: chilly for the beach
- Moderate offshore wind (14 mph): it blows floats and inflatables out to sea
- Dangerous for swimming: 5.2 ft waves every 10 s; high rip current risk
- Water at 55 °F (very cold)
Dangerous surf during beach hours. Stay out if the red flag is up, and never swim where there is no lifeguard.
Today, hour by hour
- Swimming Dangerous · 5.2 ft
5.2 ft waves every 10 s: dangerous for swimming. Stay out if the red flag is up. High rip current risk. If you're caught in a rip current, don't swim against it: swim parallel to shore and wave for help. Always follow the lifeguard's flags.
- Water 55 °F
Very cold: ease in and keep swims short.
- Sun & sunscreen UV 2 · SPF 15
Max UV 2 (low): SPF 15 sunscreen.
- Wind 14 mph
Moderate offshore wind (14 mph). Skip the inflatables: offshore wind carries them out to sea.
- Tide & sand 12:35 pm
Low tide at 12:06 am and 12:35 pm: that's when there's the most sand. High tide at 6:02 am and 6:31 pm.
We don't have data on jellyfish, sargassum or beach closures: ask the lifeguard or check with the local beach authority. How it works · The next 7 days
Beaches near Groix
Map: OpenFreeMap · © OpenMapTiles · © OpenStreetMap contributors
- Port Melin 1.0 mi · NW
- Plage de Locmaria 1.1 mi · SE
- Restrooms
- Parking
Excellent water quality 2025 season, EEA
- Plage de Porz Skedoul 1.1 mi · E
- Restrooms
- Parking
- Plage de Porz ar Roed 1.1 mi · SE
- Crique naturiste 1.1 mi · S
- Nudity allowed
- Plage de Port Mélite 1.2 mi · E
- Restrooms
- Parking
Excellent water quality 2025 season, EEA
- Plouziorek 1.4 mi · NW
- Poulziorek 1.4 mi · NW
Named beaches within 6.2 mi, nearest first. Amenities from OpenStreetMap: some may be missing or out of date. View on OpenStreetMap · Add or fix on OpenStreetMap
Beaches and amenities: © OpenStreetMap contributors (ODbL). Bathing water quality: European Environment Agency (EEA), with data from the French Ministry of Health (baignades.sante.gouv.fr).
Webcams near Groix
Webcams provided by windy.com — add a webcam
Tides in Groix
Today's high and low tides
- ▼ Low tide 12:06 am 2.6 ft
- ▲ Next high tide 6:02 am 16.2 ft · coef. 93
- ▼ Low tide 12:35 pm 2.6 ft
- ▲ High tide 6:31 pm 15.6 ft · coef. 88
↑ Rising The tide is rising. 2 h 25 min to high tide at 6:02 am.
Tide coefficient 93 for the 6:02 am high tide and 88 for the 6:31 pm high tide. Spring tides. The water rises and falls 13.6 ft between the highest high and the lowest low: a large range for this place. 70 is an average tide here; 90 and above means spring tides; below 45, neap tides. What is the tide coefficient?
2026 extremes: the highest tide of the year is on March 20 (17.0 ft) and the lowest, on August 14 (1.0 ft).
Semidiurnal: two high and two low tides a day, of similar height.
Heights above chart datum: the lowest astronomical tide (LAT), the zero of nautical charts in Europe. Astronomical prediction: wind and air pressure can raise or lower the water by a few inches, and more in a storm. Not for navigation. chart datum (LAT)
Tide coefficient and range in October
The biggest tides of the month came from October 26 to 28 (coefficient 100, 14.7 ft range). The smallest, on October 19 (coefficient 26, 4.4 ft).
Tide and solunar table · this week
| Day | Sun | Tide 1 | Tide 2 | Tide 3 | Tide 4 | Coef. | Moon | Major periods | Activity |
|---|---|---|---|---|---|---|---|---|---|
| Today, Thu 29 | 7:53 am · 6:01 pm | Low tide 12:06 am · 2.6 ft | High tide 6:02 am · 16.2 ft | Low tide 12:35 pm · 2.6 ft | High tide 6:31 pm · 15.6 ft | Coef. 93 | 85% | Major periods 2:40 am · 3:12 pm | Medium |
| Fri 30 | 7:55 am · 6:00 pm | Low tide 12:54 am · 3.3 ft | High tide 6:47 am · 15.5 ft | Low tide 1:27 pm · 3.4 ft | High tide 7:21 pm · 14.5 ft | Coef. 82 | 76% | Major periods 3:44 am · 4:16 pm | Medium |
| Sat 31 | 7:56 am · 5:58 pm | Low tide 1:47 am · 4.3 ft | High tide 7:40 am · 14.6 ft | Low tide 2:25 pm · 4.3 ft | High tide 8:26 pm · 13.3 ft | Coef. 68 | 66% | Major periods 4:47 am · 5:17 pm | Medium |
| Sun 1 | 7:58 am · 5:56 pm | Low tide 2:47 am · 5.2 ft | High tide 8:52 am · 13.7 ft | Low tide 3:31 pm · 5.1 ft | High tide 10:01 pm · 12.5 ft | Coef. 55 | Last quarter | Major periods 5:46 am · 6:14 pm | Medium |
| Mon 2 | 7:59 am · 5:55 pm | Low tide 3:56 am · 5.9 ft | High tide 10:35 am · 13.2 ft | Low tide 4:47 pm · 5.5 ft | High tide 11:41 pm · 12.5 ft | Coef. 48 | 43% | Major periods 6:40 am · 7:05 pm | Medium |
| Tue 3 | 8:01 am · 5:53 pm | Low tide 5:12 am · 6.0 ft | High tide 12:09 pm · 13.4 ft | Low tide 6:06 pm · 5.3 ft | — | Coef. 51 | 33% | Major periods 7:29 am · 7:53 pm | Medium |
| Wed 4 | 8:02 am · 5:52 pm | High tide 12:54 am · 13.1 ft | Low tide 6:26 am · 5.6 ft | High tide 1:17 pm · 14.0 ft | Low tide 7:14 pm · 4.7 ft | Coef. 59 | 23% | Major periods 8:16 am · 8:38 pm | Medium |
▲ high tide · ▼ low tide · heights above chart datum (LAT). Major periods: start time; they last 2 hours. Activity: based on the moon phase and the solunar periods.
Where this tide comes from
Tides from the Port Tudy station (TICON-4), 0.5 mi from Groix. Times and heights are its predictions.
Station data attribution: Slackwater database (https://github.com/openwatersio/slackwater-database). Source: Hart-Davis, M., Dettmering, D., Seitz, F. (2025), TICON-4: TIdal CONstants based on GESLA-4 sea-level records, SEANOE, https://doi.org/10.17882/109129. Licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Modified: see https://github.com/openwatersio/slackwater-database#modifications-to-source-data
The sea at Groix
Sea stateSea state: moderate
The waves you may find
- Most commonMost common3.1 ft
- Significant6.1 ft
- Highest expectedHighest12 ft
One wave in seven is higher than the significant height, and about 3 times a day one reaches 12 ft. Before heading out, expect waves of up to 12 ft.
Wind on the coast and offshore
Cross-offshore wind. The coast faces southwest and the wind comes off the land at an angle: calmer water near the shore, and bait and boats drift out to sea.
Wave height, next 7 daysWaves, next 7 days
Waves ease over the next few days. The biggest waves arrive on Thursday 29: 7.0 ft with a period of 11 s, from the west (moderate).
Water temperature
Water temperature →The satellite measured 3.4 °F more 2 days ago than the model gives now: the water is probably warmer than the forecast says.
Water temperature changes how fish behave: in very cold or very warm water they feed less. The water is steady these days, with no sudden changes.
Water colder than normal for late October (−4.1 °F).
Satellite: NASA MUR (JPL MUR MEaSUREs, PO.DAAC), doi:10.5067/GHGMR-4FJ04. Sources and licenses
Water temperature →Forecast from Open-Meteo (CC BY 4.0) with models from ECMWF, NOAA, Météo-France, DWD, Copernicus Marine and CAMS. Updated at 3:29 am (local time).
Nearest buoy
This is a real measurement of the sea, not a forecast. Data from Centre for Studies on Risks Environment Mobility and Urban Planning - Technical directorate Risks waters and sea (Plouzane), Ecole Centrale Nantes, via the E.U. Copernicus Marine Service. Generated using E.U. Copernicus Marine Service Information (doi:10.48670/moi-00036).
Surf in Groix today
Surf today
Good- 3.1–4.8 ft surf at the shore, a good size with some punch
- 4.3 ft swell at 9 s from the west, a bit short
- Moderate offshore wind (14 mph): it holds up and grooms the waves
- Rising tide (high tide at 6:31 pm)
- Light: First light 7:21 am · sunrise 7:53 am · sunset 6:01 pm · last light 6:33 pm
- Tide: low 12:06 am (2.6 ft), high 6:02 am (16.2 ft), low 12:35 pm (2.6 ft) and high 6:31 pm (15.6 ft). Every break has its own tide: some work at low tide and others at high tide. The tide doesn’t change the score here.
- Water at 54.5 °F: a 5/4 fullsuit with booties (and a hood if it’s windy).
- Energy: 255 kJ · Medium power
Today’s surf at a glance
The best window, 12:00 pm to 4:00 pm, has a good size and light offshore wind.
An estimate for this stretch of coast, not for a specific break: every beach or reef works its own way (its tide, bottom and angle). Check it when you get there.
Follow the flags and the lifeguards, and don’t paddle out if the surf is above your level: this score is a guide, not a substitute for what you see when you get there.
Diving in Groix today
Diving and snorkeling today
Likely visibility: poor- Some tidal current
- 3.7 ft swell at 8 s from the west: some surge on the bottom
- Light offshore wind (11 mph)
- 0.2 mph current toward the north-northwest, weak (model)
- Daylight
- Slack water today: low tide 12:06 am (11:50 pm–12:21 am), high tide 6:02 am (5:40–6:30 am), low tide 12:35 pm (12:20–12:50 pm) and high tide 6:31 pm (6:00–7:00 pm)
- Likely visibility: poor. Swell (up to 9.6 ft at 10 s) over the last few days has stirred up the water. Based on the last 24 hours of data.
- Water at 54.5 °F: a 7 mm semi-dry suit, with hood, gloves and booties.
- Snorkeling: better not, with these waves, wind or current.
- Night dive: dark from 6:33 pm. Waning gibbous (85%), rising at 8:02 pm: a bright night.
Your diving day at a glance
The best window, 4:50 pm to 5:30 pm, combines light wind and weak current, though with tidal current and some swell.
Slack water comes from the tide: in inlets, channels and between islands the water can keep running for an hour or two after. Ask the local dive shop.
Never dive alone and check with the local dive shop: this rating is a guide, not a substitute for a professional.
Dive sites, wrecks and dive shops nearby
Map: OpenFreeMap · © OpenMapTiles · © OpenStreetMap contributors
- Club subaquatique 12 mi
- Kemperle Activités Subaquatiques 12 mi
- Sperrbrecher 134 1.0 mi
- Lys Immacule 1.0 mi
- Sanaga 1.6 mi
- Edouard de Cougy 2.4 mi
- Baumann 3.0 mi
- Locqueltas 3.6 mi
- Wreck 1.9 mi
- Wreck 1.9 mi
- Club Subaquatique Lorientais 8.5 mi
- Moi, Je Plonge À L'ouest 8.7 mi
Within 12 mi. Some may be missing or closed; marine reserves usually need a permit. Open the map on OpenStreetMap · Missing one? Add it to OpenStreetMap
Wreck and reef positions are approximate and not for navigation; a wreck’s depth runs from the top of the hull to the seabed.
Sites: © OpenStreetMap contributors (ODbL). Wrecks: EMODnet Human Activities (AND-International), from UK Hydrographic Office data, CC BY 4.0. Contains public sector information licensed under the Open Government Licence v3.0.
Weather in Groix
Now in Groix
- Low / high
- 51 / 58 °F
- Rain
- 0.00 in · 0%
- Clouds
- 100%
- Humidity
- 86%
- Dew pointDew point
- 48 °F
- Visibility
- 20 mi
- UV indexUV
- 0 · low
- Air qualityAir
- Fair · 26
- Saharan dust
- No
- Pollen
- None
Pressure and fishing
- ↗ RisingRising Anglers say fish bite less for a while
- → SteadySteady · now Anglers expect normal activity
- ↘ FallingFalling Anglers say fish feed more before the change
Steady now (−0.02 inHg in 3 hours). It barely changes over the next 48 hours. Steady pressure: anglers expect normal activity. Fast changes, either way, tend to affect fishing.
Today, hour by hourHour by hour
Bars: mean wind. Dashed line: gusts. Arrows point where the wind blows to.
| Time | 12:00 am | 3:00 am | 6:00 am | 9:00 am | 12:00 pm | 3:00 pm | 6:00 pm | 9:00 pm |
|---|---|---|---|---|---|---|---|---|
| Sky | Overcast | Overcast | Overcast | Overcast | Overcast | Overcast | Overcast | Mainly clear |
| Temperature | 54° | 52° | 51° | 51° | 54° | 57° | 58° | 55° |
| Wind (mph) | 7 ENE | 12 ENE | 10 E | 14 E | 13 E | 11 E | 12 E | 12 ENE |
| Gusts | 9 | 15 | 15 | 17 | 17 | 17 | 15 | 15 |
| Waves | 7.0 ft | 6.2 ft | 5.6 ft | 5.2 ft | 4.9 ft | 4.5 ft | 3.9 ft | 3.5 ft |
| Rain | 0.00 in | 0.00 in | 0.00 in | 0.00 in | 0.00 in | 0.00 in | 0.00 in | 0.00 in |
- 3:00 am 52° 12 ENE 6.2 ft
- 6:00 am 51° 10 E 5.6 ft
- 9:00 am 51° 14 E 5.2 ft
- 12:00 pm 54° 13 E 4.9 ft
- 3:00 pm 57° 11 E 4.5 ft
- 6:00 pm 58° 12 E 3.9 ft
- 9:00 pm 55° 12 ENE 3.5 ft
- 12:00 am 52° 13 ENE 3.3 ft
Next 14 daysComing days
| Day | Sky | Low / high | Max wind | Max wave | High tides |
|---|---|---|---|---|---|
| Today · 29 | 51 / 58 °F | 14 mph E | 7.0 ft | 6:02 am · 6:31 pm | |
| Fri 30 | 48 / 59 °F | 15 mph ENE | 4.8 ft | 6:47 am · 7:21 pm | |
| Sat 31 | 48 / 57 °F | 14 mph ENE | 5.2 ft | 7:40 am · 8:26 pm | |
| Sun 1 | 49 / 58 °F | 15 mph NE | 4.5 ft | 8:52 am · 10:01 pm | |
| Mon 2 | 48 / 58 °F | 15 mph NE | 3.1 ft | 10:35 am · 11:41 pm | |
| Tue 3 | 49 / 57 °F | 13 mph NE | 2.4 ft | 12:09 pm | |
| Wed 4 | 44 / 52 °F | 12 mph ENE | 3.8 ft | 12:54 am · 1:17 pm | |
| Thu 5 | 41 / 51 °F | 13 mph ENE | 3.8 ft | 1:47 am · 2:08 pm | |
| Fri 6 | 43 / 52 °F | 12 mph ENE | 3.1 ft | 2:30 am · 2:49 pm | |
| Sat 7 | 48 / 58 °F | 13 mph ESE | 3.5 ft | 3:06 am · 3:25 pm | |
| Sun 8 | 55 / 58 °F | 12 mph SE | 4.1 ft | 3:39 am · 3:57 pm | |
| Mon 9 | 57 / 59 °F | 14 mph S | 4.6 ft | 4:10 am · 4:28 pm | |
| Tue 10 | 56 / 60 °F | 12 mph S | 4.6 ft | 4:42 am · 4:58 pm | |
| Wed 11 | 55 / 58 °F | 19 mph WSW | 5.4 ft | 5:14 am · 5:29 pm |
- Fri 30 Overcast 48° / 59° 4.8 ft
- Sat 31 Overcast 48° / 57° 5.2 ft
- Sun 1 Overcast 49° / 58° 4.5 ft
- Mon 2 Overcast 48° / 58° 3.1 ft
- Tue 3 Overcast 49° / 57° 2.4 ft
- Wed 4 Clear sky 44° / 52° 3.8 ft
- Thu 5 Mainly clear 41° / 51° 3.8 ft
Each day comes from the best model covering this spot: regional ones first (HRRR and NBM in the U.S., AROME, ICON-EU), then ECMWF; day 16, NOAA GFS. Waves: Météo-France up to day 10, then ECMWF WAM, coarser and further offshore. High tides: our own tide calculation.
- Normal Today, normal highs for late October (59 °F). Climate by month →
Forecast from Open-Meteo (CC BY 4.0) with models from ECMWF, NOAA, Météo-France, DWD, Copernicus Marine and CAMS. Updated at 3:29 am (local time).
The sun in Groix
Sunrise and sunset
- First light 6:45 am
- Full dark 7:09 pm
- Civil dawn 7:21 am
- Civil dusk 6:33 pm
- Solar noon 12:58 pm (29° high)
- Daylight 10 h 8 min (−3 min)
- Evening golden hour 5:17 pm
- Full dark 7:09 pm
Golden hour and the day-night map
Today the sun is 92,335,318 mi away and looks 32′ 11″ across.
The moon in Groix
Moon phase and position
Today the moon is 226,618 mi away and looks 32′ 45″ across.
Solunar periods
Today's activity: medium- 2:40–4:40 am Major · the moon passes overhead · high activity
- 3:12–5:12 pm Major · the moon passes underfoot · high activity
- 11:52 am–12:52 pm Minor · moonset · medium activity
- 7:32–8:32 pm Minor · moonrise · medium activity
According to solunar theory, fish feed more when the moon passes overhead or underfoot (major periods, about 2 h) and when it rises or sets (minor periods, 1 h). It works best around new and full moon.
Upcoming moon phases
2026 moon calendar →- Last quarter Sun, Nov 1 · 9:29 pmNov 1 in 3 days
- New moon Mon, Nov 9 · 8:03 amNov 9 in 11 days
- First quarter Tue, Nov 17 · 12:48 pmNov 17 in 19 days
- Full moon Tue, Nov 24 · 3:54 pmNov 24 in 26 days
Next perigee (the moon at its closest to Earth): November 25, 223,281 mi away.
Where to fish in Groix
Piers, ramps and tackle shops nearby
Map: OpenFreeMap · © OpenMapTiles · © OpenStreetMap contributors
- l'estacade 6.9 mi
- Jetée 7.6 mi
- Jetée de Locmaria 1.2 mi
- Jetty 8.9 mi
- Boat ramp 0.4 mi
- Boat ramp 0.5 mi
- Boat ramp 1.2 mi
- Port de la Pointe 6.8 mi
- Port Tudy 0.5 mi
- Filo'Fish 7.3 mi
- Le Douarin Equipement 7.7 mi
- Fuel dock 6.9 mi
Within 9.3 mi. A spot may be missing or closed. Open the map on OpenStreetMap · Missing one? Add it to OpenStreetMap
Spots: © OpenStreetMap contributors (ODbL) and Overture Maps.
Water depth
Deepens quicklyThe bottom deepens quickly: 33 ft of water 950 ft from shore. It reaches 164 ft at 2.6 mi.
From the shoreline (1.2 mi from Groix) out to sea, heading southwest.
How far from shore
- 16 ft deep460 ft
- 33 ft deep950 ft
- 66 ft deep0.6 mi
- 164 ft deep2.6 mi
For fishing, swimming and diving
- Shore fishing. Deep water close in: about 9.5 ft just 330 ft out. Good for casting from rocks, jetties or the beach itself; current and surf hit harder here.
- Swimming. The water gets deeper little by little, but a few dozen yards out you can no longer stand.
- Diving. Shore diving works here: 33 ft at 950 ft and 66 ft at 0.6 mi from shore.
Source: EMODnet Bathymetry DTM 2024 (CC BY 4.0), cells of about 380 ft; depth at the lowest astronomical tide. For reference only: not for navigation or anchoring.
Nearest lighthouse
.JPG)
Port Tudy jetty lights 0.6 mi northeast
Other lighthouses nearby: Phare de la Pointe des Chats (2.0 mi southeast), Phare de Pen-Men (2.6 mi west).
Data from Wikidata. For reference only: not for navigation. Wikidata · Sources and licenses
Tides near GroixTides nearby
- Larmor-Plage5.7 mi
- Port-Louis6.6 mi
- Ploemeur6.7 mi
- Locmiquélic8.0 mi
- Riantec8.4 mi
- Lorient8.5 mi
- Guidel-Plage9.4 mi
- Lanester10 mi
- Quéven11 mi
- Étel12 mi
Groix at a glance
- Town or city of about 2,429 people. Coordinates: 47.639° N, 3.454° W.
- It is 71 mi southeast of Brest, the main place in Brittany. The sun rises 6 min earlier and sets 3 min earlier than in Brest.
- The nearest tide station, Port Tudy, is 0.5 mi to the northeast.
- Its coast faces southwest.
- Beaches and harbors nearby: Port Melin (1.1 mi), Plage les Grands Sables (1.5 mi), Port Nâl (1.5 mi).
Questions about GroixQuestions
What time is high tide today in Groix?
Today in Groix there are high tides at 6:02 am (16.2 ft) and 6:31 pm (15.6 ft) and low tides at 12:06 am and 12:35 pm. Tide coefficient 93.
What time is sunset today in Groix?
At 6:01 pm. There is light until the end of civil twilight, at 6:33 pm.
What time is sunrise tomorrow in Groix?
At 7:55 am. First light comes at 6:46 am.
What phase is the moon today?
Waning gibbous, 85% illuminated. New moon on Mon, Nov 9 · 8:03 am.
When are the next spring tides?
From November 9 to 11.
What are today's solunar periods?
Major 2:40–4:40 am, Minor 11:52 am–12:52 pm, Major 3:12–5:12 pm, Minor 7:32–8:32 pm. Today's activity is medium.
What's the weather like today in Groix?
Overcast, from 51 °F to 58 °F, with a moderate breeze from the east-northeast (12 mph) and a 0% chance of rain.
How is the sea today in Groix?
Moderate (Douglas 4): 6.1 ft waves with a period of 10.9 s from the west. The water is 54.5 °F.
When is the best time to visit Groix?
The best time to visit Groix is from July to August: highs of 72 °F, about 7 rainy days a month and 8 hours of sunshine a day.
Can I use this data for navigation?
No. These are predictions for fishing and leisure; for navigation, use the official publications.
Where this data comes from
Tide: Port Tudy station, with constants from TICON-4 (Hart-Davis, Dettmering and Seitz, 2025, SEANOE), licensed CC BY 4.0, via Slackwater database (changes). Sun and moon: our own calculation with astronomy-engine. Places: GeoNames (CC BY 4.0). Coastline: © OpenStreetMap contributors (ODbL).